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## Complete Summary

#### GUIDELINE TITLE

ACC/AHA/ESC 2006 guidelines for management of patients with ventricular
arrhythmias and the prevention of sudden cardiac death. A report of the
American College of Cardiology/American Heart Association Task Force and
the European Society of Cardiology Committee for Practice Guidelines
(Writing Committee to Develop Guidelines for Management of Patients With
Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death).

#### BIBLIOGRAPHIC SOURCE(S)

European Heart Rhythm Association, Heart Rhythm Society, Zipes DP, Camm
AJ, Borggrefe M, Buxton AE, Chaitman B, Fromer M, Gregoratos G, Klein G,
Moss AJ, Myerburg RJ, Priori SG, Quinones MA, Roden DM, Silka MJ, Tracy
C, Smith SC Jr, Jacobs AK, Adams CD, Antman EM, Anderson JL, Hunt SA,
Halperin JL, Nishimura R, Ornato JP, Page RL, Riegel B, Priori SG, Blanc
JJ, Budaj A, Camm AJ, Dean V, Deckers JW, Despres C, Dickstein K,
Lekakis J, McGregor K, Metra M, Morais J, Osterspey A, Tamargo JL,
Zamorano JL, American College of Cardiology, American Heart Association
Task Force, European Society of Cardiology Committee for Practice
Guidelines. ACC/AHA/ESC 2006 guidelines for management of patients with
ventricular arrhythmias and the prevention of sudden cardiac death: a
report of the American College of Cardiology/American Heart Association
Task Force and the European Society \[trunc\]. J Am Coll Cardiol 2006
Sep 5;48(5):e247-346. \[1085 references\]
[PubMed](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16949478)

#### GUIDELINE STATUS

This is the current release of the guideline.

### \*\* REGULATORY ALERT \*\*

#### FDA WARNING/REGULATORY ALERT

**Note from the National Guideline Clearinghouse**: This guideline
references a drug(s)/intervention(s) for which important revised
regulatory and/or warning information has been released.

-   [June 8, 2007, Troponin-I
    Immunoassay](http://www.fda.gov/medwatch/safety/2007/safety07.htm#Architect):
    Class I Recall of all lots of the Architect Stat Troponin-I
    Immunoassay. The assay may report falsely elevated or falsely
    decreased results at and near a low level, which may impact patient
    treatment.

### COMPLETE SUMMARY CONTENT

 \*\* REGULATORY ALERT \*\*\
 SCOPE\
 METHODOLOGY - including Rating Scheme and Cost Analysis\
 RECOMMENDATIONS\
 EVIDENCE SUPPORTING THE RECOMMENDATIONS\
 BENEFITS/HARMS OF IMPLEMENTING THE GUIDELINE RECOMMENDATIONS\
 CONTRAINDICATIONS\
 QUALIFYING STATEMENTS\
 IMPLEMENTATION OF THE GUIDELINE\
 INSTITUTE OF MEDICINE (IOM) NATIONAL HEALTHCARE QUALITY REPORT
CATEGORIES\
 IDENTIFYING INFORMATION AND AVAILABILITY\
 DISCLAIMER

### SCOPE

#### DISEASE/CONDITION(S)

-   Ventricular arrhythmias

-   Sudden cardiac death

#### GUIDELINE CATEGORY

Diagnosis\
Evaluation\
Management\
Prevention\
Risk Assessment\
Treatment

#### CLINICAL SPECIALTY

Cardiology\
Emergency Medicine\
Family Practice\
Internal Medicine

#### INTENDED USERS

Physicians

#### GUIDELINE OBJECTIVE(S)

-   To update and combine the previously published recommendations into
    one source approved by the major cardiology organizations in the
    United States and Europe

-   To produce guidelines that improve the effectiveness of care,
    optimize patient outcomes, and affect the overall cost of care
    favorably by focusing resources on the most effective strategies

#### TARGET POPULATION

-   Patients with ventricular arrhythmias

-   Patients at risk for ventricular arrhythmias or sudden cardiac
    \"death\" episodes

#### INTERVENTIONS AND PRACTICES CONSIDERED

**Diagnosis/Evaluation**

1.  History and physical examination

2.  Resting electrocardiogram (ECG)

3.  Exercise testing

4.  Ambulatory electrocardiography

5.  Electrocardiographic techniques and measurements (T wave alternans,
    signal-averaged electrocardiogram (SAECG), heart rate variability
    (HRV), baroflex sensitivity and heart rate turbulence)

6.  Electrophysiological testing

7.  Left ventricular function and imaging

    -   Echocardiograph

    -   Exercise testing with an imaging modality (echocardiography or
        nuclear perfusion \[single-photon emission computed tomography
        (SPECT)\])

    -   Cardiac magnetic resonance imaging

    -   Cardiac computed tomography

    -   Radionuclide angiography

    -   Coronary angiography

**Management/Treatment**

1.  Cardiopulmonary resuscitation

2.  Automated external defibrillation

3.  Management of causes and factors contributing to cardiac arrest
    (electrolyte disturbances, mechanical factors, volume depletion)

4.  Direct current cardioversion

5.  Transvenous catheter placement

6.  Pharmacologic treatment

    -   Antiarrhythmic agents (e.g. amiodarone, procainamide, lidocaine,
        sotalol, quinidine, mexiletine

    -   Isoproterenol

    -   Calcium channel blockers

    -   Potassium and magnesium salts

    -   Antidigitalis antibodies

7.  Acute and long term pacing

8.  Overdrive pacing

9.  Spinal cord modulation

10. Left cardiac sympathetic denervation

11. Coronary revascularization

12. Implantation of an implantable cardioverter defibrillator (ICD)

13. Adjunct treatments for ICD (catheter ablation, surgical resection,
    pharmacological therapy)

14. Lifestyle modification

15. Management of comorbid conditions

16. Ventricular arrhythmias and sudden cardiac death related to specific
    populations

    -   Athletes

    -   Gender and pregnancy

    -   Elderly patients

    -   Pediatric patients

    -   Patients with ICDs

    -   Drug-induced arrhythmias

#### MAJOR OUTCOMES CONSIDERED

-   Restoration and maintenance of sinus rhythm

-   Successful ablation of ectopic focus

-   Hemodynamic function

-   Quality of life

-   Adverse effects of treatment (e.g., antiarrhythmia drug toxicities)

-   Prevention of cardiac arrest

-   Successful resuscitation of cardiac arrest

-   Mortality rate

### METHODOLOGY

#### METHODS USED TO COLLECT/SELECT EVIDENCE

Searches of Electronic Databases

#### DESCRIPTION OF METHODS USED TO COLLECT/SELECT THE EVIDENCE

The committee conducted comprehensive searching of the scientific and
medical literature on ventricular arrhythmias and sudden cardiac death
(SCD). Literature searching was limited to publications on humans and in
English from 1990 to 2006. The search parameters were extended for
selected topics when a historical reference was needed or if limited
studies existed in English. In addition to broad-based searching on
ventricular arrhythmias and SCD, specific targeted searches were
performed on ventricular arrhythmias and SCD and the following
subtopics: mechanisms, substrates, clinical presentations,
electrocardiogram, exercise testing, echocardiography, imaging,
electrophysiological testing, drug therapy (antiarrhythmic and
nonantiarrhythmic), implantable and external cardioverter devices,
ablation, surgery, acute specific arrhythmias (e.g., acute coronary
syndrome, heart failure, stable sustained monomorphic ventricular
tachycardia, torsades de pointes), specific pathology (e.g., congenital
heart disease, myocarditis, endocrine disorders, renal failure),
cardiomyopathies, genetic arrhythmias, structurally normal hearts,
athletes, elderly, gender, pediatric, and drug-induced arrhythmias. The
complete list of keywords is beyond the scope of this section. The
committee reviewed all compiled reports from computerized searches and
conducted additional manual searching. Literature citations were
generally restricted to published manuscripts appearing in journals in
the Index Medicus. Because of the scope and importance of certain
ongoing clinical trials and other emerging information, published
abstracts were cited in the text when they were the only published
information available.

#### NUMBER OF SOURCE DOCUMENTS

Not stated

#### METHODS USED TO ASSESS THE QUALITY AND STRENGTH OF THE EVIDENCE

Weighting According to a Rating Scheme (Scheme Given)

#### RATING SCHEME FOR THE STRENGTH OF THE EVIDENCE

**Levels of Evidence**

-   **Level of Evidence A**: Data derived from multiple randomized
    clinical trials or meta-analyses.

-   **Level of Evidence B**: Data derived from a single randomized
    trial, or nonrandomized studies.

-   **Level of Evidence C**: Only consensus opinion of experts, case
    studies, or standard-of-care.

#### METHODS USED TO ANALYZE THE EVIDENCE

Review of Published Meta-Analyses\
Systematic Review with Evidence Tables

#### DESCRIPTION OF THE METHODS USED TO ANALYZE THE EVIDENCE

Not stated

#### METHODS USED TO FORMULATE THE RECOMMENDATIONS

Expert Consensus

#### DESCRIPTION OF METHODS USED TO FORMULATE THE RECOMMENDATIONS

Writing Committee members were selected with attention to cardiovascular
subspecialties, broad geographical representation, and involvement in
academic medicine and clinical practice. The Writing Committee on the
Management of Patients With Ventricular Arrhythmias and Prevention of
Sudden Cardiac Death also included members of the American College of
Cardiology (ACC)/ American Heart Association (AHA) Task Force on
Practice Guidelines, European Society of Cardiology (ESC) Committee on
Practice Guidelines, ACC Board of Trustees, ACC Board of Governors, ESC
Board, the European Heart Rhythm Association (EHRA), and the Heart
Rhythm Society (HRS).

The schema for classification of recommendations and level of evidence
is summarized in Table 2 of the original full length guideline document,
which also illustrates how the grading system provides an estimate of
the size of treatment effect and an estimate of the certainty of the
treatment effect.

Recommendations with respect to therapy have considered the following:

1.  The therapy to be offered (implantable cardioverter defibrillator
    \[ICD\], antiarrhythmic drugs, surgery, and miscellaneous other
    treatments)

2.  The point at which therapy is offered (primary prevention for those
    who are at risk but have not yet had a life-threatening ventricular
    arrhythmia or sudden cardiac \"death\" episode, or secondary for
    those patients who have already experienced such arrhythmias or
    events)

3.  The purpose of therapy (life preservation or symptom
    reduction/improved quality of life)

4.  The etiology of the arrhythmia substrate (coronary heart disease
    \[CHD\], cardiomyopathy, or other conditions)

5.  The functional status of the patient (New York Heart Association
    \[NYHA\] functional class)

6.  The state of left ventricular (LV) function (LV ejection fraction
    \[LVEF\])

7.  The specific arrhythmia concerned (e.g., sustained monomorphic VT,
    polymorphic VT, and ventricular fibrillation \[VF\])

Not all therapeutic combinations are clinically relevant, and many have
no evidence base and probably will not have one in the future because of
the lack of clinical relevance or the relative rarity of the particular
grouping. In many instances, the probable value of therapy may be
reasonably inferred by the response of similar patients to specific
therapies.

Recommendations for prophylactic ICD implantation based on ejection
fractions (EFs) have been inconsistent because clinical investigators
have chosen different EFs for enrollment in trials of therapy, average
values of the EF in such trials have been substantially lower than the
cutoff value for enrollment, and subgroup analyses of clinical trial
populations based on EF have not been consistent in their implications.
Substantial differences between guidelines have resulted. However, no
trial has randomized patients with an intermediate range of EFs. For
instance, there is no trial that has specifically studied patients with
an LVEF between 31% and 35%, yet recommendations have been set for such
patients on the basis of data derived from trials that studied groups
with EFs less than or equal to 30%, others that enrolled patients with
an EF less than or equal to 35%, and one trial that enrolled patients
with an EF less than or equal to 40%. Recognizing these inconsistencies,
this Guideline Writing Committee decided to construct recommendations to
apply to patients with an EF less than or equal to a range of values.
The highest appropriate class of recommendation was then based on all
trials that recruited patients with EFs within this range. In this way,
potential conflicts between guidelines were reduced and errors due to
drawing false conclusions relating to unstudied patient groups were
minimized (see Table 3 in the original full-length guideline document).

#### RATING SCHEME FOR THE STRENGTH OF THE RECOMMENDATIONS

**Classification of Recommendations**

-   **Class I**: Conditions for which there is evidence and/or general
    agreement that a given procedure/treatment is beneficial, useful,
    and effective.

-   **Class II**: Conditions for which there is conflicting evidence
    and/or a divergence of opinion about the usefulness/efficacy of a
    procedure or treatment.

    -   **Class IIa**: Weight of evidence/opinion is in favor of
        usefulness/efficacy.

    -   **Class IIb**: Usefulness/efficacy is less well established by
        evidence/opinion.

-   **Class III**: Conditions for which there is evidence and/or general
    agreement that a procedure/treatment is not useful or effective and
    in some cases may be harmful.

#### COST ANALYSIS

Published cost analyses were reviewed.

#### METHOD OF GUIDELINE VALIDATION

External Peer Review\
Internal Peer Review

#### DESCRIPTION OF METHOD OF GUIDELINE VALIDATION

The document was reviewed by 2 official reviewers nominated by the
American College of Cardiology (ACC), 2 official reviewers nominated by
the American Heart Association (AHA), 2 official reviewers nominated by
the European Society of Cardiology (ESC), 1 official reviewer from the
ACC/AHA Task Force on Practice Guidelines, reviewers from the European
Heart Rhythm Association (EHRA) and Heart Rhythm Society (HRS), and 18
content reviewers, including members from American College of Cardiology
Foundation (ACCF) Clinical Electrophysiology Committee, AHA Council on
Clinical Cardiology, Electrocardiography, and Arrhythmias, and AHA
Advanced Cardiac Life Support Subcommittee.

### RECOMMENDATIONS

#### MAJOR RECOMMENDATIONS

Definitions for the weight of the evidence (A-C) and classes of
recommendations (I-III) can be found at the end of the \"Major
Recommendations\" field.

**[Classification of Ventricular Arrhythmias and Sudden Cardiac
Death]{.underline}**

This classification table is provided for direction and introduction of
the guidelines.

**Table. Classification of Ventricular Arrhythmias**

+---------------+---------------+-------------------------------------+
| **C           |               |                                     |
| lassification |               |                                     |
| by Clinical   |               |                                     |
| P             |               |                                     |
| resentation** |               |                                     |
+---------------+---------------+-------------------------------------+
| He            | Asymptomatic  | The absence of symptoms that could  |
| modynamically |               | result from an arrhythmia           |
| stable        |               |                                     |
+---------------+---------------+-------------------------------------+
|               | Minimal       | Patient reports palpitations felt   |
|               | symptoms      | in either the chest, throat, or     |
|               | (e.g.         | neck as described by the following: |
|               | palpitations) |                                     |
|               |               | -   Heartbeat sensations that feel  |
|               |               |     like pounding or racing         |
|               |               |                                     |
|               |               | -   An unpleasant awareness of      |
|               |               |     heartbeat                       |
|               |               |                                     |
|               |               | -   Feeling skipped beats or a      |
|               |               |     pause                           |
+---------------+---------------+-------------------------------------+
| He            | Presyncope    | Patient reports presyncope as       |
| modynamically |               | described by the following:         |
| unstable      |               |                                     |
|               |               | -   Dizziness                       |
|               |               |                                     |
|               |               | -   Lightheadedness                 |
|               |               |                                     |
|               |               | -   Feeling faint                   |
|               |               |                                     |
|               |               | -   \"Graying out\"                 |
+---------------+---------------+-------------------------------------+
|               | Syncope       | Sudden loss of consciousness with   |
|               |               | loss of postural tone not related   |
|               |               | to anesthesia, with spontaneous     |
|               |               | recovery as reported by the patient |
|               |               | or observer. Patient may experience |
|               |               | syncope when supine                 |
+---------------+---------------+-------------------------------------+
|               | Sudden        | Death from an unexpected            |
|               | cardiac death | circulatory arrest, usually due to  |
|               |               | a cardiac arrhythmia occurring      |
|               |               | within an hour of the onset of      |
|               |               | symptoms                            |
+---------------+---------------+-------------------------------------+
|               | Sudden        | Death from an unexpected            |
|               | cardiac       | circulatory arrest, usually due to  |
|               | arrest        | a cardiac arrhythmia occurring      |
|               |               | within an hour of the onset of      |
|               |               | symptoms, in whom medical           |
|               |               | intervention (e.g., defibrillation) |
|               |               | reverses the event                  |
+---------------+---------------+-------------------------------------+
| **C           |               |                                     |
| lassification |               |                                     |
| by            |               |                                     |
| Electroc      |               |                                     |
| ardiography** |               |                                     |
+---------------+---------------+-------------------------------------+
| Nonsustained  |               | Three or more beats in duration,    |
| VT            |               | terminating spontaneously in less   |
|               |               | than 30 seconds\                    |
|               |               | \                                   |
|               |               | VT is a cardiac arrhythmia of three |
|               |               | or more consecutive complexes in    |
|               |               | duration emanating from the         |
|               |               | ventricles at a rate of greater     |
|               |               | than 100 bpm (cycle length less     |
|               |               | than 600 ms)                        |
+---------------+---------------+-------------------------------------+
|               | Monomorphic   | Nonsustained VT with a single QRS   |
|               |               | morphology.                         |
+---------------+---------------+-------------------------------------+
|               | Polymorphic   | Nonsustained VT with a changing QRS |
|               |               | morphology at cycle length between  |
|               |               | 600 and 180 ms                      |
+---------------+---------------+-------------------------------------+
| Sustained VT  |               | VT greater than 30 s in duration    |
|               |               | and/or requiring termination due to |
|               |               | hemodynamic compromise in less than |
|               |               | 30 s.                               |
+---------------+---------------+-------------------------------------+
|               | Monomorphic   | Sustained VT with a stable single   |
|               |               | QRS morphology                      |
+---------------+---------------+-------------------------------------+
|               | Polymorphic   | Sustained VT with a changing or     |
|               |               | multiform QRS morphology at cycle   |
|               |               | length between 600 and 180 ms       |
+---------------+---------------+-------------------------------------+
| Bundle-branch |               | VT due to re-entry involving the    |
| re-entrant    |               | His-Purkinje system, usually with   |
| tachycardia   |               | LBBB morphology; this usually       |
|               |               | occurs in the setting of            |
|               |               | cardiomyopathy                      |
+---------------+---------------+-------------------------------------+
| Bidirectional |               | VT with a beat-to-beat alternans in |
| VT            |               | the QRS frontal plane axis, often   |
|               |               | associated with digitalis toxicity. |
+---------------+---------------+-------------------------------------+
| Torsades de   |               | Characterized by VT associated with |
| pointes       |               | a long QT or QTc, and               |
|               |               | electrocardiographically            |
|               |               | characterized by twisting of the    |
|               |               | peaks of the QRS complexes around   |
|               |               | the isoelectric line during the     |
|               |               | arrhythmia:                         |
|               |               |                                     |
|               |               | -   \"Typical,\" initiated          |
|               |               |     following \"short-long-short\"  |
|               |               |     coupling intervals.             |
|               |               |                                     |
|               |               | -   Short coupled variant initiated |
|               |               |     by normal-short coupling.       |
+---------------+---------------+-------------------------------------+
| Ventricular   |               | A regular (cycle length variability |
| flutter       |               | 30 ms or less) ventricular          |
|               |               | arrhythmia approximately 300 bpm    |
|               |               | (cycle length---200 ms) with a      |
|               |               | monomorphic appearance; no          |
|               |               | isoelectric interval between        |
|               |               | successive QRS complexes.           |
+---------------+---------------+-------------------------------------+
| Ventricular   |               | Rapid, usually more than 300        |
| fibrillation  |               | bpm/200 ms (cycle length 180 ms or  |
|               |               | less), grossly irregular            |
|               |               | ventricular rhythm with marked      |
|               |               | variability in QRS cycle length,    |
|               |               | morphology, and amplitude.          |
+---------------+---------------+-------------------------------------+
| **C           |               |                                     |
| lassification |               |                                     |
| by Disease    |               |                                     |
| Entity**      |               |                                     |
+---------------+---------------+-------------------------------------+
| Chronic       |               |                                     |
| coronary      |               |                                     |
| heart disease |               |                                     |
+---------------+---------------+-------------------------------------+
| Heart failure |               |                                     |
+---------------+---------------+-------------------------------------+
| Congenital    |               |                                     |
| heart disease |               |                                     |
+---------------+---------------+-------------------------------------+
| Neurological  |               |                                     |
| disorders     |               |                                     |
+---------------+---------------+-------------------------------------+
| Structurally  |               |                                     |
| normal hearts |               |                                     |
+---------------+---------------+-------------------------------------+
| Sudden infant |               |                                     |
| death         |               |                                     |
| syndrome      |               |                                     |
+---------------+---------------+-------------------------------------+
| Car           | Dilated       |                                     |
| diomyopathies | c             |                                     |
|               | ardiomyopathy |                                     |
+---------------+---------------+-------------------------------------+
|               | Hypertrophic  |                                     |
|               | c             |                                     |
|               | ardiomyopathy |                                     |
+---------------+---------------+-------------------------------------+
|               | A             |                                     |
|               | rrhythmogenic |                                     |
|               | right         |                                     |
|               | ventricular   |                                     |
|               | c             |                                     |
|               | ardiomyopathy |                                     |
+---------------+---------------+-------------------------------------+

bpm = beats per minutes; LBBB = left bundle-branch block; ms =
milliseconds; s = seconds; VT = ventricular tachycardia.

**[Clinical Presentations of Patients with Ventricular Arrhythmias and
Sudden Cardiac Death]{.underline}**

Ventricular arrhythmias can occur in individuals with or without cardiac
disorders. There is a great deal of overlap between clinical
presentations (see Table below titled \"Clinical Presentations of
Patients With Ventricular  Arrhythmias and Sudden Cardiac Death\") and
severity and type of heart disease. For example, stable and
well-tolerated ventricular tachycardia (VT) can occur in the individual
with previous myocardial infarction (MI) and impaired ventricular
function. The prognosis and management are individualized according to
symptom burden and severity of underlying heart disease in addition to
the clinical presentation.

**Table. Clinical Presentations of Patients With Ventricular Arrhythmias
and Sudden Cardiac Death**

+-----------------------------------------------------------------------+
| -   Asymptomatic individuals with or without electrocardiographic     |
|     abnormalities                                                     |
|                                                                       |
| -   Persons with symptoms potentially attributable to ventricular     |
|     arrhythmias                                                       |
|                                                                       |
|     -   Palpitations                                                  |
|                                                                       |
|     -   Dyspnea                                                       |
|                                                                       |
|     -   Chest pain                                                    |
|                                                                       |
|     -   Syncope and presyncope                                        |
|                                                                       |
| -   Ventricular tachycardia that is hemodynamically stable            |
|                                                                       |
| -   Ventricular tachycardia that is not hemodynamically stable        |
|                                                                       |
| -   Cardiac arrest                                                    |
|                                                                       |
|     -   Asystole (sinus arrest, atrioventricular block)               |
|                                                                       |
|     -   Ventricular tachycardia                                       |
|                                                                       |
|     -   Ventricular fibrillation                                      |
|                                                                       |
|     -   Pulseless electrical activity                                 |
+-----------------------------------------------------------------------+

**[Resting Electrocardiography]{.underline}**

*Class I*

Resting 12-lead electrocardiogram (ECG) is indicated in all patients who
are evaluated for ventricular arrhythmias. (*Level of Evidence: **A***)

**[Exercise Testing]{.underline}**

*Class I*

1.  Exercise testing is recommended in adult patients with ventricular
    arrhythmias who have an intermediate or greater probability of
    having coronary heart disease (CHD) by age, gender, and symptoms\*
    to provoke ischemic changes or ventricular arrhythmias. (*Level of
    Evidence: **B***) *\*See Table 4 in the \"ACC/AHA 2002 Guideline
    Update for Exercise Testing\" for further explanation of CHD
    probability. (See \"Availability of Companion Documents\" field in
    this summary)*

2.  Exercise testing, regardless of age, is useful in patients with
    known or suspected exercise-induced ventricular arrhythmias,
    including catecholaminergic VT, to provoke the arrhythmia, achieve a
    diagnosis, and determine the patient\'s response to tachycardia.
    (*Level of Evidence: **B***)

*Class IIa*

Exercise testing can be useful in evaluating response to medical or
ablation therapy in patients with known exercise-induced ventricular
arrhythmias. (*Level of Evidence: **B***)

*Class IIb*

1.  Exercise testing may be useful in patients with ventricular
    arrhythmias and a low probability of CHD by age, gender, and
    symptoms.\* (*Level of Evidence: **C***) *\*See Table 4 in the
    \"ACC/AHA 2002 Guideline Update for Exercise Testing\" for further
    explanation of CHD probability.(See \"Availability of Companion
    Documents\" field in this summary)*

2.  Exercise testing may be useful in the investigation of isolated
    premature ventricular complexes (PVCs) in middle-aged or older
    patients without other evidence of CHD. (*Level of Evidence: **C***)

*Class III*

See Table 1 in the \"ACC/AHA 2002 Guideline Update for Exercise
Testing\" for contraindications. (*Level of Evidence: **B***) (See
\"Availability of Companion Documents\" field in this summary)

**[Ambulatory Electrocardiography]{.underline}**

*Class I*

1.  Ambulatory electrocardiogram (ECG) is indicated when there is a need
    to clarify the diagnosis by detecting arrhythmias, QT interval
    changes, T-wave alternans (TWA), or ST changes, to evaluate risk, or
    to judge therapy. (*Level of Evidence: **A***)

2.  Event monitors are indicated when symptoms are sporadic to establish
    whether or not they are caused by transient arrhythmias. (*Level of
    Evidence: **B***)

3.  Implantable recorders are useful in patients with sporadic symptoms
    suspected to be related to arrhythmias such as syncope when a
    symptom-rhythm correlation cannot be established by conventional
    diagnostic techniques. (*Level of Evidence: **B***)

**[Electrocardiographic Techniques and Measurements]{.underline}**

*Class IIa*

It is reasonable to use TWA to improve the diagnosis and risk
stratification of patients with ventricular arrhythmias or who are at
risk for developing life threatening ventricular arrhythmias. (*Level of
Evidence: **A***)

*Class IIb*

ECG techniques such as signal-averaged ECG (SAECG), heart rate
variability (HRV), baroflex sensitivity, and heart rate turbulence may
be useful to improve the diagnosis and risk stratification of patients
with ventricular arrhythmias or who are at risk of developing life
threatening ventricular arrhythmias. (*Level of Evidence: **B***)

**[Left Ventricular Function and Imaging]{.underline}**

*Class I*

1.  Echocardiography is recommended in patients with ventricular
    arrhythmias who are suspected of having structural heart disease.
    (*Level of Evidence: **B***)

2.  Echocardiography is recommended for the subset of patients at high
    risk for the development of serious ventricular arrhythmias or
    sudden cardiac death (SCD), such as those with dilated,
    hypertrophic, or right ventricular (RV) cardiomyopathies, acute
    myocardial infarction (AMI) survivors, or relatives of patients with
    inherited disorders associated with SCD. (*Level of Evidence:
    **B***)

3.  Exercise testing with an imaging modality (echocardiography or
    nuclear perfusion \[single-photon emission computed tomography
    (SPECT)\]) is recommended to detect silent ischemia in patients with
    ventricular arrhythmias who have an intermediate probability of
    having CHD by age, symptoms, and gender and in whom ECG assessment
    is less reliable because of digoxin use, left ventricular
    hypertrophy (LVH), greater than 1-mm ST-segment depression at rest,
    Wolff-Parkinson-White (WPW) syndrome, or left bundle branch block
    (LBBB). (*Level of Evidence: **B***)

4.  Pharmacological stress testing with an imaging modality
    (echocardiography or myocardial perfusion SPECT) is recommended to
    detect silent ischemia in patients with ventricular arrhythmias who
    have an intermediate probability of having CHD by age, symptoms, and
    gender and are physically unable to perform a symptom-limited
    exercise test. (*Level of Evidence: **B***)

*Class IIa*

1.  Magnetic resonance imaging (MRI), cardiac computed tomography (CT),
    or radionuclide angiography can be useful in patients with
    ventricular arrhythmias when echocardiography does not provide
    accurate assessment of left ventricular (LV) and RV function and/or
    evaluation of structural changes. (*Level of Evidence: **B***)

2.  Coronary angiography can be useful in establishing or excluding the
    presence of significant obstructive CHD in patients with
    life-threatening ventricular arrhythmias or in survivors of SCD, who
    have an intermediate or greater probability of having CHD by age,
    symptoms, and gender. (*Level of Evidence: **C***)

3.  LV imaging can be useful in patients undergoing biventricular
    pacing. (*Level of Evidence: **C***)

**[Electrophysiological (EP) Testing]{.underline}**

**Electrophysiological Testing in Patients with Coronary Heart Disease**

*Class I*

1.  EP testing is recommended for diagnostic evaluation of patients with
    remote MI with symptoms suggestive of ventricular tachyarrhythmias,
    including palpitations, presyncope, and syncope. (*Level of
    Evidence: **B***)

2.  EP testing is recommended in patients with CHD to guide and assess
    the efficacy of VT ablation. (*Level of Evidence: **B***)

3.  EP testing is useful in patients with CHD for the diagnostic
    evaluation of wide-QRS-complex tachycardias of unclear mechanism.
    (*Level of Evidence: **C***)

*Class IIa*

EP testing is reasonable for risk stratification in patients with remote
MI, Nonsustained ventricular tachycardia (NSVT), and LV ejection
fraction equal to or less than 40%. (*Level of Evidence: **B***)

**Electrophysiological Testing in Patients with Syncope**

*Class I*

EP testing is recommended in patients with syncope of unknown cause with
impaired LV function or structural heart disease. (*Level of Evidence:
**B***)

*Class IIa*

EP testing can be useful in patients with syncope when bradyarrhythmias
or tachyarrhythmias are suspected and in whom noninvasive diagnostic
studies are not conclusive. (*Level of Evidence: **B***)

**[Implantable and External Cardioverter Devices]{.underline}**

**Ablation**

*Class I*

1.  Ablation is indicated in patients who are otherwise at low risk for
    SCD and have sustained predominantly monomorphic VT that is drug
    resistant, who are drug intolerant, or who do not wish long-term
    drug therapy. (*Level of Evidence: **C***)

2.  Ablation is indicated in patients with bundle-branch reentrant VT.
    (*Level of Evidence: **C**)*

3.  Ablation is indicated as adjunctive therapy in patients with an ICD
    who are receiving multiple shocks as a result of sustained VT that
    is not manageable by reprogramming or changing drug therapy or who
    do not wish long-term drug therapy. (*Level of Evidence: **C***)

4.  Ablation is indicated in patients with WPW syndrome resuscitated
    from sudden cardiac arrest due to atrial fibrillation (AF) and rapid
    conduction over the accessory pathway causing ventricular
    fibrillation (VF). (*Level of Evidence: **B***)

*Class IIa*

1.  Ablation can be useful therapy in patients who are otherwise at low
    risk for SCD and have symptomatic nonsustained monomorphic VT that
    is drug resistant, who are drug intolerant or who do not wish
    long-term drug therapy. (*Level of Evidence: **C***)

2.  Ablation can be useful therapy in patients who are otherwise at low
    risk for SCD and have frequent symptomatic predominantly monomorphic
    PVCs that are drug resistant or who are drug intolerant or who do
    not wish long-term drug therapy. (*Level of Evidence: **C***)

3.  Ablation can be useful in symptomatic patients with WPW syndrome who
    have accessory pathways with refractory periods less than 240
    milliseconds (ms) in duration. (*Level of Evidence: **B***)

*Class IIb*

1.  Ablation of Purkinje fiber potentials may be considered in patients
    with ventricular arrhythmia storm consistently provoked by PVCs of
    similar morphology. (*Level of Evidence: **C***)

2.  Ablation of asymptomatic PVCs may be considered when the PVCs are
    very frequent to avoid or treat tachycardia-induced cardiomyopathy.
    (*Level of Evidence: **C***)

*Class III*

Ablation of asymptomatic relatively infrequent PVCs is not indicated.
(*Level of Evidence: **C***)

**[Acute Management of Specific Arrhythmias]{.underline}**

**Management of Cardiac Arrest**

*Class I*

1.  After establishing the presence of definite, suspected, or impending
    cardiac arrest, the first priority should be activation of a
    response team capable of identifying the specific mechanism and
    carrying out prompt intervention. (*Level of Evidence: **B***)

2.  Cardiopulmonary resuscitation (CPR) should be implemented
    immediately after contacting a response team. (*Level of Evidence:
    **A***)

3.  In an out-of-hospital setting, if an automated external
    defibrillator (AED) is available, it should be applied immediately
    and shock therapy administered according to the algorithms contained
    in the documents on CPR developed by the AHA in association with the
    International Liaison Committee on Resuscitation (ILCOR) and/or the
    European Resuscitation Council (ERC). (*Level of Evidence: **C***)

4.  For victims with ventricular tachyarrhythmic mechanisms of cardiac
    arrest, when recurrences occur after a maximally defibrillating
    shock (generally 360 joules (J) for monophasic defibrillators),
    intravenous amiodarone should be the preferred antiarrhythmic drug
    for attempting a stable rhythm after further defibrillations.
    (*Level of Evidence: **B***)

5.  For recurrent ventricular tachyarrhythmias or non-tachyarrhythmic
    mechanisms of cardiac arrest, it is recommended to follow the
    algorithms contained in the documents on CPR developed by the AHA in
    association with ILCOR and/or the ERC. (*Level of Evidence: **C***)

6.  Reversible causes and factors contributing to cardiac arrest should
    be managed during advanced life support, including management of
    hypoxia, electrolyte disturbances, mechanical factors, and volume
    depletion. (*Level of Evidence: **C***)

*Class IIa*

For response times greater than or equal to 5 minutes, a brief (less
than 90 to 180 seconds) period of CPR is reasonable prior to attempting
defibrillation. (*Level of Evidence: **B**)*

*Class IIb*

A single precordial thump may be considered by health care professional
providers when responding to a witnessed cardiac arrest. (*Level of
Evidence: **C***)

**Ventricular Tachycardia Associated With Low Troponin Myocardial
Infarction**

*Class I*

Patients presenting with sustained VT in whom low-level elevations in
cardiac biomarkers of myocyte injury/necrosis are documented should be
treated similarly to patients who have sustained VT and in whom no
biomarker rise is documented. (*Level of Evidence: **C***)

**Sustained Monomorphic Ventricular Tachycardia**

*Class I*

1.  Wide-QRS tachycardia should be presumed to be VT if the diagnosis is
    unclear. (*Level of Evidence: **C***)

2.  Direct current cardioversion with appropriate sedation is
    recommended at any point in the treatment cascade in patients with
    suspected sustained monomorphic VT with hemodynamic compromise.
    (*Level of Evidence: **C***)

*Class IIa*

1.  Intravenous procainamide (or ajmaline in some European countries) is
    reasonable for initial treatment of patients with stable sustained
    monomorphic VT. (*Level of Evidence: **B***)

2.  Intravenous amiodarone is reasonable in patients with sustained
    monomorphic VT that is hemodynamically unstable, refractory to
    conversion with countershock, or recurrent despite procainamide or
    other agents. (*Level of Evidence: **C***)

3.  Transvenous catheter pace termination can be useful to treat
    patients with sustained monomorphic VT that is refractory to
    cardioversion or is frequently recurrent despite antiarrhythmic
    medication. (*Level of Evidence: **C***)

*Class IIb*

Intravenous lidocaine might be reasonable for the initial treatment of
patients with stable sustained monomorphic VT specifically associated
with acute myocardial ischemia or infarction. (*Level of Evidence:
**C***)

*Class III*

Calcium channel blockers such as verapamil and diltiazem should not be
used in patients to terminate wide-QRS-complex tachycardia of unknown
origin, especially in patients with a history of myocardial dysfunction.
(*Level of Evidence: **C***)

**Repetitive Monomorphic Ventricular Tachycardia**

*Class IIa*

Intravenous amiodarone, beta blockers, and intravenous procainamide (or
sotalol or ajmaline in Europe) can be useful for treating repetitive
monomorphic VT in the context of coronary disease and idiopathic VT.
(*Level of Evidence: **C***)

**Polymorphic VT**

*Class I*

1.  Direct current cardioversion with appropriate sedation as necessary
    is recommended for patients with sustained polymorphic VT with
    hemodynamic compromise and is reasonable at any point in the
    treatment cascade. (*Level of Evidence: **B***)

2.  Intravenous beta blockers are useful for patients with recurrent
    polymorphic VT, especially if ischemia is suspected or cannot be
    excluded. (*Level of Evidence: **B***)

3.  Intravenous loading with amiodarone is useful for patients with
    recurrent polymorphic VT in the absence of abnormal repolarization
    related to congenital or acquired LQTS. (*Level of Evidence: **C***)

4.  Urgent angiography with a view to revascularization should be
    considered for patients with polymorphic VT when myocardial ischemia
    cannot be excluded. (*Level of Evidence: **C***)

*Class IIb*

Intravenous lidocaine may be reasonable for treatment of polymorphic VT
specifically associated with acute myocardial ischemia or infarction.
(*Level of Evidence: **C***)

**Torsades de Pointes**

*Class I*

1.  Withdrawal of any offending drugs and correction of electrolyte
    abnormalities are recommended in patients presenting with torsades
    de pointes. (*Level of Evidence: **A***)

2.  Acute and long-term pacing is recommended for patients presenting
    with torsades de pointes due to heart block and symptomatic
    bradycardia. (*Level of Evidence: **A***)

*Class IIa*

1.  Management with intravenous magnesium sulfate is reasonable for
    patients who present with LQTS and few episodes of torsades de
    pointes. Magnesium is not likely to be effective in patients with a
    normal QT interval. (*Level of Evidence: **B***)

2.  Acute and long-term pacing is reasonable for patients who present
    with recurrent pause-dependent torsades de pointes. (*Level of
    Evidence: **B***)

3.  Beta blockade combined with pacing is reasonable acute therapy for
    patients who present with torsades de pointes and sinus bradycardia.
    (*Level of Evidence: **C***)

4.  Isoproterenol is reasonable as temporary treatment in acute patients
    who present with recurrent pause-dependent torsades de pointes who
    do not have congenital LQTS. (*Level of Evidence: **B***)

*Class IIb*

1.  Potassium repletion to 4.5 to 5 mmol/L may be considered for
    patients who present with torsades de pointes. (*Level of Evidence:
    **B***)

2.  Intravenous lidocaine or oral mexiletine may be considered in
    patients who present with LQT3 and torsades de pointes. (*Level of
    Evidence: **C***)

**Incessant Ventricular Tachycardia**

*Class I*

Revascularization and beta blockade followed by intravenous
antiarrhythmic drugs such as procainamide or amiodarone are recommended
for patients with recurrent or incessant polymorphic VT due to acute
myocardial ischemia. (*Level of Evidence: **C***)

*Class IIa*

Intravenous amiodarone or procainamide followed by VT ablation can be
effective in the management of patients with frequently recurring or
incessant monomorphic VT. (*Level of Evidence: **B***)

*Class IIb*

1.  Intravenous amiodarone and intravenous beta blockers separately or
    together may be reasonable in patients with VT storm. (*Level of
    Evidence: **C***)

2.  Overdrive pacing or general anesthesia may be considered for
    patients with frequently recurring or incessant VT. (*Level of
    Evidence: **C***)

3.  Spinal cord modulation may be considered for some patients with
    frequently recurring or incessant VT. (*Level of Evidence: **C***)

**[Ventricular Arrhythmia and Sudden Cardiac Death Related to Specific
Pathology]{.underline}**

**Left Ventricular Dysfunction Due to Prior Myocardial Infarction**

*Class I*

1.  Aggressive attempts should be made to treat heart failure (HF) that
    may be present in some patients with LV dysfunction due to prior MI
    and ventricular tachyarrhythmias. (*Level of Evidence: **C***)

2.  Aggressive attempts should be made to treat myocardial ischemia that
    may be present in some patients with ventricular tachyarrhythmias.
    (*Level of Evidence: **C***)

3.  Coronary revascularization is indicated to reduce the risk of SCD in
    patients with VF when direct, clear evidence of acute myocardial
    ischemia is documented to immediately precede the onset of VF.
    (*Level of Evidence: **B***)

4.  If coronary revascularization cannot be carried out and there is
    evidence of prior MI and significant LV dysfunction, the primary
    therapy of patients resuscitated from VF should be the implantable
    cardioverter defibrillator (ICD) in patients who are receiving
    chronic optimal medical therapy and those who have reasonable
    expectation of survival with a good functional status for more than
    1 year. (*Level of Evidence: **A***)

5.  ICD therapy is recommended for primary prevention to reduce total
    mortality by a reduction in SCD in patients with LV dysfunction due
    to prior MI who are at least 40 days post-MI, have an LVEF less than
    or equal to 30% to 40%, are New York Heart Association (NYHA)
    functional class II or III, are receiving chronic optimal medical
    therapy, and who have reasonable expectation of survival with a good
    functional status for more than 1 year. (*Level of Evidence: **A***)
    (See Section 1.2 in the original full-text guideline document.)

6.  The ICD is effective therapy to reduce mortality by a reduction in
    SCD in patients with LV dysfunction due to prior MI who present with
    hemodynamically unstable sustained VT, are receiving chronic optimal
    medical therapy, and who have reasonable expectation of survival
    with a good functional status for more than 1 year. (*Level of
    Evidence: **A***)

*Class IIa*

1.  Implantation of an ICD is reasonable in patients with LV dysfunction
    due to prior MI who are at least 40 days post-MI, have an LVEF of
    less than or equal to 30% to 35%, are NYHA functional class I on
    chronic optimal medical therapy, and who have reasonable expectation
    of survival with a good functional status for more than 1 y. (*Level
    of Evidence: **B***) (See Section 1.2 in the original full-text
    guideline document)

2.  Amiodarone, often in combination with beta blockers, can be useful
    for patients with LV dysfunction due to prior MI and symptoms due to
    VT unresponsive to beta-adrenergic-- blocking agents. (*Level of
    Evidence: **B***)

3.  Sotalol is reasonable therapy to reduce symptoms resulting from VT
    for patients with LV dysfunction due to prior MI unresponsive to
    beta-blocking agents. (*Level of Evidence: **C***)

4.  Adjunctive therapies to the ICD, including catheter ablation or
    surgical resection, and pharmacological therapy with agents such as
    amiodarone or sotalol are reasonable to improve symptoms due to
    frequent episodes of sustained VT or VF in patients with LV
    dysfunction due to prior MI. (*Level of Evidence: **C***)

5.  Amiodarone is reasonable therapy to reduce symptoms due to recurrent
    hemodynamically stable VT for patients with LV dysfunction due to
    prior MI who cannot or refuse to have an ICD implanted. (*Level of
    Evidence: **C***)

6.  Implantation is reasonable for treatment of recurrent ventricular
    tachycardia in patients post-MI with normal or near normal
    ventricular function who are receiving chronic optimal medical
    therapy and who have reasonable expectation of survival with a good
    functional status for more than 1 year. (*Level of Evidence: **C***)

*Class IIb*

1.  Curative catheter ablation or amiodarone may be considered in lieu
    of ICD therapy to improve symptoms in patients with LV dysfunction
    due to prior MI and recurrent hemodynamically stable VT whose LVEF
    is greater than 40%. (*Level of Evidence: **B***)

2.  Amiodarone may be reasonable therapy for patients with LV
    dysfunction due to prior MI with an ICD indication, as defined
    above, in patients who cannot or refuse to have an ICD implanted.
    (*Level of Evidence: **C***)

*Class III*

1.  Prophylactic antiarrhythmic drug therapy is not indicated to reduce
    mortality in patients with asymptomatic nonsustained ventricular
    arrhythmias. (*Level of Evidence: **B***)

2.  Class IC antiarrhythmic drugs in patients with a past history of MI
    should not be used. (*Level of Evidence: **A***)

**Valvular Heart Disease**

*Class I*

Patients with valvular heart disease and ventricular arrhythmias should
be evaluated and treated following current recommendations for each
disorder. (*Level of Evidence: **C***)

*Class IIb*

The effectiveness of mitral valve repair or replacement to reduce the
risk of SCD in patients with mitral valve prolapse, severe mitral
regurgitation, and serious ventricular arrhythmias is not well
established. (*Level of Evidence: **C***)

**Congenital Heart Disease**

*Class I*

1.  ICD implantation is indicated in patients with congenital heart
    disease who are survivors of cardiac arrest after evaluation to
    define the cause of the event and exclude any reversible causes. ICD
    implantation is indicated in patients who are receiving chronic
    optimal medical therapy and who have reasonable expectation of
    survival with a good functional status for more than 1 year. (*Level
    of Evidence: **B***)

2.  Patients with congenital heart disease and spontaneous sustained VT
    should undergo invasive hemodynamic and EP evaluation. Recommended
    therapy includes catheter ablation or surgical resection to
    eliminate VT. If that is not successful, ICD implantation is
    recommended. (*Level of Evidence: **C***)

*Class IIa*

Invasive hemodynamic and EP evaluation is reasonable in patients with
congenital heart disease and unexplained syncope and impaired
ventricular function. In the absence of a defined and reversible cause,
ICD implantation is reasonable in patients who are receiving chronic
optimal medical therapy and who have reasonable expectation of survival
with a good functional status for more than 1 year (*Level of Evidence:
**B***)

*Class IIb*

EP testing may be considered for patients with congenital heart disease
and ventricular couplets or NSVT to determine the risk of a sustained
ventricular arrhythmia. (*Level of Evidence: **C***)

*Class III*

Prophylactic antiarrhythmic therapy is not indicated for asymptomatic
patients with congenital heart disease and isolated PVCs. (*Level of
Evidence: **C***)

**Metabolic and Inflammatory Conditions**

*Myocarditis, Rheumatic Disease, and Endocarditis*

*Class I*

1.  Temporary pacemaker insertion is indicated in patients with
    symptomatic bradycardia and/or heart block during the acute phase of
    myocarditis. (*Level of Evidence: **C***)

2.  Acute aortic regurgitation associated with VT should be treated
    surgically unless otherwise contraindicated. (*Level of Evidence:
    **C***)

3.  Acute endocarditis complicated by aortic or annular abscess and
    atrioventricular (AV) block should be treated surgically unless
    otherwise contraindicated. (*Level of Evidence: **C***)

*Class IIa*

1.  ICD implantation can be beneficial in patients with life-threatening
    ventricular arrhythmias who are not in the acute phase of
    myocarditis, who are receiving chronic optimal medical therapy, and
    who have reasonable expectation of survival with a good functional
    status for more than 1 year. (*Level of Evidence: **C***)

2.  Antiarrhythmic therapy can be useful in patients with symptomatic
    NSVT or sustained VT during the acute phase of myocarditis. (*Level
    of Evidence: **C***)

*Class III*

ICD implantation is not indicated during the acute phase of myocarditis.
(*Level of Evidence: **C***)

*Infiltrative Cardiomyopathies*

*Class I*

In addition to managing the underlying infiltrative cardiomyopathy,
life-threatening arrhythmias should be treated in the same manner that
such arrhythmias are treated in patients with other cardiomyopathies,
including the use of ICD and pacemakers in patients who are receiving
chronic optimal medical therapy and who have reasonable expectation of
survival with a good functional status for more than 1 year. (*Level of
Evidence: **C***)

*Endocrine Disorders and Diabetes*

*Class I*

1.  The management of ventricular arrhythmias secondary to endocrine
    disorders should address the electrolyte (potassium, magnesium, and
    calcium) imbalance and the treatment of the underlying
    endocrinopathy. (*Level of Evidence: **C***)

2.  Persistent life-threatening ventricular arrhythmias that develop in
    patients with endocrine disorders should be treated in the same
    manner that such arrhythmias are treated in patients with other
    diseases, including use of ICD and pacemaker implantation as
    required in those who are receiving chronic optimal medical therapy
    and who have reasonable expectation of survival with a good
    functional status for more than 1 year. (*Level of Evidence: **C***)

3.  Patients with diabetes with ventricular arrhythmias should generally
    be treated in the same manner as patients without diabetes. (*Level
    of Evidence: **A***)

*End-Stage Renal Failure*

*Class I*

1.  The acute management of ventricular arrhythmias in end-stage renal
    failure should immediately address hemodynamic status and
    electrolyte (potassium, magnesium, and calcium) imbalance. (*Level
    of Evidence: **C***)

2.  Life-threatening ventricular arrhythmias, especially in patients
    awaiting renal transplantation, should be treated conventionally,
    including the use of ICD and pacemaker as required, in patients who
    are receiving chronic optimal medical therapy and who have
    reasonable expectation of survival with a good functional status for
    more than 1 year. (*Level of Evidence: **C***)

*Obesity, Dieting, and Anorexia*

*Class I*

Life-threatening ventricular arrhythmias in patients with obesity,
anorexia, or when dieting should be treated in the same manner that such
arrhythmias are treated in patients with other diseases, including ICD
and pacemaker implantation as required. Patients receiving ICD
implantation should be receiving chronic optimal medical therapy and
have reasonable expectation of survival with a good functional status
for more than 1 year. (*Level of Evidence: **C***)

*Class IIa*

Programmed weight reduction in obesity and carefully controlled
re-feeding in anorexia can effectively reduce the risk of ventricular
arrhythmias and SCD. (*Level of Evidence: **C***)

*Class III*

Prolonged, unbalanced, very low calorie, semistarvation diets are not
recommended; they may be harmful and provoke life-threatening
ventricular arrhythmias. (*Level of Evidence: **C***)

**Pericardial Diseases**

*Class I*

Ventricular arrhythmias that develop in patients with pericardial
disease should be treated in the same manner that such arrhythmias are
treated in patients with other diseases including ICD and pacemaker
implantation as required. Patients receiving ICD implantation should be
receiving chronic optimal medical therapy and have reasonable
expectation of survival with a good functional status for more than 1
year. (*Level of Evidence: **C***)

**Pulmonary Arterial Hypertension**

*Class III*

Prophylactic antiarrhythmic therapy generally is not indicated for
primary prevention of SCD in patients with pulmonary arterial
hypertension (PAH) or other pulmonary conditions. (*Level of Evidence:
**C***)

**Transient Arrhythmias of Reversible Cause**

*Class I*

1.  Myocardial revascularization should be performed, when appropriate,
    to reduce the risk of SCD in patients experiencing cardiac arrest
    due to VF or polymorphic VT in the setting of acute ischemia or MI.
    (*Level of Evidence: **C***)

2.  Unless electrolyte abnormalities are proved to be the cause,
    survivors of cardiac arrest due to VF or polymorphic VT in whom
    electrolyte abnormalities are discovered in general should be
    evaluated and treated in a manner similar to that of cardiac arrest
    without electrolyte abnormalities. (*Level of Evidence: **C***)

3.  Patients who experience sustained monomorphic VT in the presence of
    antiarrhythmic drugs or electrolyte abnormalities should be
    evaluated and treated in a manner similar to that of patients with
    VT without electrolyte abnormalities or antiarrhythmic drugs
    present. Antiarrhythmic drugs or electrolyte abnormalities should
    not be assumed to be the sole cause of sustained monomorphic VT.
    (*Level of Evidence: **B***)

4.  Patients who experience polymorphic VT in association with prolonged
    QT interval due to antiarrhythmic medications or other drugs should
    be advised to avoid exposure to all agents associated with QT
    prolongation. A list of such drugs can be found on the Web site
    [www.torsades.org](http://www.torsades.org/medical-pros/history.htm).(*Level
    of Evidence: **B***)

**[Ventricular Arrhythmias Associated with
Cardiomyopathies]{.underline}**

**Dilated Cardiomyopathy (Nonischemic)**

*Class I*

1.  EP testing is useful to diagnose bundle-branch reentrant tachycardia
    and to guide ablation in patients with nonischemic dilated
    cardiomyopathy (DCM). (*Level of Evidence: **C***)

2.  EP testing is useful for diagnostic evaluation in patients with
    nonischemic DCM with sustained palpitations, wide-QRS-complex
    tachycardia, presyncope, or syncope. (*Level of Evidence: **C***)

3.  An ICD should be implanted in patients with nonischemic DCM and
    significant LV dysfunction who have sustained VT or VF, are
    receiving chronic optimal medical therapy, and who have reasonable
    expectation of survival with a good functional status for more than
    1 year. (*Level of Evidence: **A***)

4.  ICD therapy is recommended for primary prevention to reduce total
    mortality by a reduction in SCD in patients with nonischemic DCM who
    have an LV ejection fraction (LVEF) less than or equal to 30% to
    35%, are NYHA functional class II or III, who are receiving chronic
    optimal medical therapy, and who have reasonable expectation of
    survival with a good functional status for more than 1 year. (*Level
    of Evidence: **B***) (See Section 1.2 in the original full-text
    guideline document.)

*Class IIa*

1.  ICD implantation can be beneficial for patients with unexplained
    syncope, significant LV dysfunction, and nonischemic DCM who are
    receiving chronic optimal medical therapy and who have reasonable
    expectation of survival with a good functional status for more than
    1 year. (*Level of Evidence: **C***)

2.  ICD implantation can be effective for termination of sustained VT in
    patients with normal or near normal ventricular function and
    nonischemic DCM who are receiving chronic optimal medical therapy
    and who have reasonable expectation of survival with a good
    functional status for more than 1 year. (*Level of Evidence: **C***)

*Class IIb*

1.  Amiodarone may be considered for sustained VT or VF in patients with
    nonischemic DCM. (*Level of Evidence: **C***)

2.  Placement of an ICD might be considered in patients who have
    nonischemic DCM, LVEF of less than or equal to 30% to 35%, who are
    NYHA functional *class I* receiving chronic optimal medical therapy,
    and who have reasonable expectation of survival with a good
    functional status for more than 1 year. (*Level of Evidence: **C***)
    (See Section 1.2 in the original full-text guideline document).

**Hypertrophic Cardiomyopathy (HCM)**

*Class I*

ICD therapy should be used for treatment in patients with HCM who have
sustained VT and/or VF and who are receiving chronic optimal medical
therapy and who have reasonable expectation of survival with a good
functional status for more than 1 year. (*Level of Evidence: **B***)

*Class IIa*

1.  ICD implantation can be effective for primary prophylaxis against
    SCD in patients with HCM who have 1 or more major risk factor (see
    Table 7 in the original full-text guideline document) for SCD and
    who are receiving chronic optimal medical therapy and in patients
    who have reasonable expectation of survival with a good functional
    status for more than 1 year. (*Level of Evidence: **C***)

2.  Amiodarone therapy can be effective for treatment in patients with
    HCM with a history of sustained VT and/or VF when an ICD is not
    feasible. (*Level of Evidence: **C***)

*Class IIb*

1.  EP testing may be considered for risk assessment for SCD in patients
    with HCM. (*Level of Evidence: **C***)

2.  Amiodarone may be considered for primary prophylaxis against SCD in
    patients with HCM who have 1 or more major risk factor for SCD (see
    Table 7 in the original full-text guideline document) if ICD
    implantation is not feasible. (*Level of Evidence: **C***)

**Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)**

*Class I*

ICD implantation is recommended for the prevention of SCD in patients
with ARVC with documented sustained VT or VF who are receiving chronic
optimal medical therapy and who have reasonable expectation of survival
with a good functional status for more than 1 year. (*Level of Evidence:
**B***)

*Class IIa*

1.  ICD implantation can be effective for the prevention of SCD in
    patients with ARVC with extensive disease, including those with LV
    involvement, 1 or more affected family member with SCD, or
    undiagnosed syncope when VT or VF has not been excluded as the cause
    of syncope, who are receiving chronic optimal medical therapy, and
    who have reasonable expectation of survival with a good functional
    status for more than 1 year. (*Level of Evidence: **C***)

2.  Amiodarone or sotalol can be effective for treatment of sustained VT
    or VF in patients with ARVC when ICD implantation is not feasible.
    (*Level of Evidence: **C***)

3.  Ablation can be useful as adjunctive therapy in management of
    patients with ARVC with recurrent VT, despite optimal antiarrhythmic
    drug therapy. (*Level of Evidence: **C***)

*Class IIb*

EP testing might be useful for risk assessment of SCD in patients with
ARVC. (*Level of Evidence: **C***)

**Neuromuscular Disorders**

*Class I*

Patients with neuromuscular disorders who have ventricular arrhythmias
should generally be treated in the same manner as patients without
neuromuscular disorders. (*Level of Evidence: **A***)

*Class IIb*

Permanent pacemaker insertion may be considered for neuromuscular
diseases such as myotonic muscular dystrophy, Kearns-Sayre syndrome, Erb
dystrophy, and peroneal muscular atrophy with any degree of AV block
(including first-degree AV block) with or without symptoms, because
there may be unpredictable progression of AV conduction disease. (*Level
of Evidence: **B***)

**[Heart Failure]{.underline}**

*Class I*

1.  ICD therapy is recommended for secondary prevention of SCD in
    patients who survived VF or hemodynamically unstable VT, or VT with
    syncope and who have an LVEF less than or equal to 40%, who are
    receiving chronic optimal medical therapy, and who have a reasonable
    expectation of survival with a good functional status for more than
    1 year. (*Level of Evidence: **A***)

2.  ICD therapy is recommended for primary prevention to reduce total
    mortality by a reduction in SCD in patients with LV dysfunction due
    to prior MI who are at least 40 day post-MI, have an LVEF less than
    or equal to 30% to 40%, are NYHA functional class II or III
    receiving chronic optimal medical therapy, and who have reasonable
    expectation of survival with a good functional status for more than
    1 year. (*Level of Evidence: **A***) (See section 1.2 in the
    original full-text guideline document)

3.  ICD therapy is recommended for primary prevention to reduce total
    mortality by a reduction in SCD in patients with nonischemic heart
    disease who have an LVEF less than or equal to 30% to 35%, are NYHA
    functional class II or III, are receiving chronic optimal medical
    therapy, and who have reasonable expectation of survival with a good
    functional status for more than 1 year. (*Level of Evidence: **B***)
    (See Section 1.2 in the original full-text guideline document.)

4.  Amiodarone, sotalol, and/or other beta blockers are recommended
    pharmacological adjuncts to ICD therapy to suppress symptomatic
    ventricular tachyarrhythmias (both sustained and nonsustained) in
    otherwise optimally treated patients with HF. (*Level of Evidence:
    **C***)

5.  Amiodarone is indicated for the suppression of acute hemodynamically
    compromising ventricular or supraventricular tachyarrhythmias when
    cardioversion and/or correction of reversible causes have failed to
    terminate the arrhythmia or prevent its early recurrence. (*Level of
    Evidence: **B***)

*Class IIa*

1.  ICD therapy combined with biventricular pacing can be effective for
    primary prevention to reduce total mortality by a reduction in SCD
    in patients with NYHA functional class III or IV, are receiving
    optimal medical therapy, in sinus rhythm with a QRS complex of at
    least 120 ms, and who have reasonable expectation of survival with a
    good functional status for more than 1 y. (*Level of Evidence:
    **B***)

2.  ICD therapy is reasonable for primary prevention to reduce total
    mortality by a reduction in SCD in patients with LV dysfunction due
    to prior MI who are at least 40 day post-MI, have an LVEF of less
    than or equal to 30% to 35%, are NYHA functional class I, are
    receiving chronic optimal medical therapy, and have reasonable
    expectation of survival with a good functional status for more than
    1 y. (*Level of Evidence: **B***) (See Section 1.2 in the original
    full-text guideline document.)

3.  ICD therapy is reasonable in patients who have recurrent stable VT,
    a normal or near normal LVEF, and optimally treated HF and who have
    a reasonable expectation of survival with a good functional status
    for more than 1 year. (*Level of Evidence: **C***)

4.  Biventricular pacing in the absence of ICD therapy is reasonable for
    the prevention of SCD in patients with NYHA functional class III or
    IV HF, an LVEF less than or equal to 35%, and a QRS complex equal to
    or wider than 160 ms (or at least 120 ms in the presence of other
    evidence of ventricular dyssynchrony) who are receiving chronic
    optimal medical therapy and who have reasonable expectation of
    survival with a good functional status for more than 1 year. (*Level
    of Evidence: **B**)*

*Class IIb*

1.  Amiodarone, sotalol, and/or beta blockers may be considered as
    pharmacological alternatives to ICD therapy to suppress symptomatic
    ventricular tachyarrhythmias (both sustained and nonsustained) in
    optimally treated patients with HF for whom ICD therapy is not
    feasible. (*Level of Evidence: **C***)

2.  ICD therapy may be considered for primary prevention to reduce total
    mortality by a reduction in SCD in patients with nonischemic heart
    disease who have an LVEF of less than or equal to 30% to 35%, are
    NYHA functional class I receiving chronic optimal medical therapy,
    and who have a reasonable expectation of survival with a good
    functional status for more than 1 year. (*Level of Evidence: **B***)
    (See Section 1.2 in the original full-text guideline document.)

**[Genetic Arrhythmia Syndromes]{.underline}**

**Long QT Syndrome**

*Class I*

1.  Lifestyle modification is recommended for patients with an LQTS
    diagnosis (clinical and/or molecular). (*Level of Evidence: **B***)

2.  Beta blockers are recommended for patients with an LQTS clinical
    diagnosis (i.e., in the presence of prolonged QT interval). (*Level
    of Evidence: **B***)

3.  Implantation of an ICD along with use of beta blockers is
    recommended for LQTS patients with previous cardiac arrest and who
    have reasonable expectation of survival with a good functional
    status for more than 1 year. (*Level of Evidence: **A***)

*Class IIa*

1.  Beta blockers can be effective to reduce SCD in patients with a
    molecular LQTS analysis and normal QT interval. (*Level of Evidence:
    **B***)

2.  Implantation of an ICD with continued use of beta blockers can be
    effective to reduce SCD in LQTS patients experiencing syncope and/or
    VT while receiving beta blockers and who have reasonable expectation
    of survival with a good functional status for more than 1 year.
    (*Level of Evidence: **B**)*

*Class IIb*

1.  Left cardiac sympathetic neural denervation may be considered for
    LQTS patients with syncope, torsades de pointes, or cardiac arrest
    while receiving beta blockers. (*Level of Evidence: **B***)

2.  Implantation of an ICD with the use of beta blockers may be
    considered for prophylaxis of SCD for patients in categories
    possibly associated with higher risk of cardiac arrest such as LQT2
    and LQT3 and who have reasonable expectation of survival with a good
    functional status for more than 1 year. (*Level of Evidence: **B***)

**Brugada Syndrome**

*Class I*

An ICD is indicated for Brugada syndrome patients with previous cardiac
arrest receiving chronic optimal medical therapy and who have reasonable
expectation of survival with a good functional status for more than 1
year (*Level of Evidence: **C***)

*Class IIa*

1.  An ICD is reasonable for Brugada syndrome patients with spontaneous
    ST-segment elevation in V~1~, V~2~, or V~3~ who have had syncope
    with or without mutations demonstrated in the SCN5A gene and who
    have reasonable expectation of survival with a good functional
    status for more than 1 year. (*Level of Evidence: **C***)

2.  Clinical monitoring for the development of a spontaneous ST-segment
    elevation pattern is reasonable for the management of patients with
    ST-segment elevation induced only with provocative pharmacological
    challenge with or without symptoms. (*Level of Evidence: **C***)

3.  An ICD is reasonable for Brugada syndrome patients with documented
    VT that has not resulted in cardiac arrest and who have reasonable
    expectation of survival with a good functional status for more than
    1 year. (*Level of Evidence: **C***)

4.  Isoproterenol can be useful to treat an electrical storm in the
    Brugada syndrome. (*Level of Evidence: **C***)

*Class IIb*

1.  EP testing may be considered for risk stratification in asymptomatic
    Brugada syndrome patients with spontaneous ST elevation with or
    without a mutation in the SCN5A gene. (*Level of Evidence: **C***)

2.  Quinidine might be reasonable for the treatment of electrical storm
    in patients with Brugada syndrome. (*Level of Evidence: **C***)

**Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT)**

*Class I*

1.  Beta blockers are indicated for patients who are clinically
    diagnosed with CPVT on the basis of the presence of spontaneous or
    documented stress-induced ventricular arrhythmias. (*Level of
    Evidence: **C***)

2.  Implantation of an ICD with use of beta blockers is indicated for
    patients with CPVT who are survivors of cardiac arrest and who have
    reasonable expectation of survival with a good functional status for
    more than 1 year. (*Level of Evidence: **C***)

*Class IIa*

1.  Beta blockers can be effective in patients without clinical
    manifestations when the diagnosis of CPVT is established during
    childhood based on genetic analysis. (*Level of Evidence: **C***)

2.  Implantation of an ICD with the use of beta blockers can be
    effective for affected patients with CPVT with syncope and/or
    documented sustained VT while receiving beta blockers and who have
    reasonable expectation of survival with a good functional status for
    more than 1 year. (*Level of Evidence: **C**)*

*Class IIb*

Beta blockers may be considered for patients with CPVT who were
genetically diagnosed in adulthood and never manifested clinical
symptoms of tachyarrhythmias. (*Level of Evidence: **C***)

**[Arrhythmias in Structurally Normal Hearts]{.underline}**

**Idiopathic Ventricular Tachycardia**

*Class I*

Catheter ablation is useful in patients with structurally normal hearts
with symptomatic, drug-refractory VT arising from the RV or LV or in
those who are drug intolerant or who do not desire long-term drug
therapy. (*Level of Evidence: **C***)

*Class IIa*

1.  EP testing is reasonable for diagnostic evaluation in patients with
    structurally normal hearts with palpitations or suspected outflow
    tract VT. (*Level of Evidence: **B***)

2.  Drug therapy with beta blockers and/or calcium channel blockers
    (and/or IC agents in RV outflow tract \[RVOT\] VT) can be useful in
    patients with structurally normal hearts with symptomatic VT arising
    from the RV. (*Level of Evidence: **C***)

3.  ICD implantation can be effective therapy for the termination of
    sustained VT in patients with normal or near normal ventricular
    function and no structural heart disease who are receiving chronic
    optimal medical therapy and who have reasonable expectation of
    survival for more than 1 year. (*Level of Evidence: **C***)

**Electrolyte Disturbances**

*Class I*

Potassium (and magnesium) salts are useful in treating ventricular
arrhythmias secondary to hypokalemia (or hypomagnesmia) resulting from
diuretic use in patients with structurally normal hearts. (*Level of
Evidence: **B***)

*Class IIa*

1.  It is reasonable to maintain serum potassium levels above 4.0 mM/L
    in any patient with documented life-threatening ventricular
    arrhythmias and a structurally normal heart. (*Level of Evidence:
    **C**)*

2.  It is reasonable to maintain serum potassium levels above 4.0 mM/L
    in patients with acute MI. (*Level of Evidence: **B***)

3.  Magnesium salts can be beneficial in the management of VT secondary
    to digoxin toxicity in patients with structurally normal hearts.
    (*Level of Evidence: **B***)

**Alcohol**

*Class I*

1.  Complete abstinence from alcohol is recommended in cases where there
    is a suspected correlation between alcohol intake and ventricular
    arrhythmias. (*Level of Evidence: **C***)

2.  Persistent life-threatening ventricular arrhythmias despite
    abstinence from alcohol should be treated in the same manner that
    such arrhythmias are treated in patients with other diseases,
    including an ICD, as required, in patients receiving chronic optimal
    medical therapy and who have reasonable expectation of survival for
    more than 1 year. (*Level of Evidence: **C***)

**Smoking**

*Class I*

Smoking should be strongly discouraged in all patients with suspected or
documented ventricular arrhythmias and/or aborted SCD. (*Level of
Evidence: **B***)

**Lipids**

*Class I*

Statin therapy is beneficial in patients with CHD to reduce the risk of
vascular events, possibly ventricular arrhythmias, and SCD. (*Level of
Evidence: **A***)

*Class IIb*

n-3 polyunsaturated fatty acid supplementation may be considered for
patients with ventricular arrhythmias and underlying CHD. (*Level of
Evidence: **B***)

**[Ventricular Arrhythmia and Sudden Cardiac Death Related to Specific
Populations]{.underline}**

**Athletes**

*Class I*

1.  Preparticipation history and physical examination, including family
    history of premature or SCD and specific evidence of cardiovascular
    diseases such as cardiomyopathies and ion channel abnormalities, is
    recommended in athletes. (*Level of Evidence: **C***)

2.  Athletes presenting with rhythm disorders, structural heart disease,
    or other signs or symptoms suspicious for cardiovascular disorders
    should be evaluated as any other patient but with recognition of the
    potential uniqueness of their activity. (*Level of Evidence: **C***)

3.  Athletes presenting with syncope should be carefully evaluated to
    uncover underlying cardiovascular disease or rhythm disorder.
    (*Level of Evidence: **B***)

4.  Athletes with serious symptoms should cease competition while
    cardiovascular abnormalities are being fully evaluated. (*Level of
    Evidence: **C***)

*Class IIb*

Twelve-lead ECG and possibly echocardiography may be considered as
preparticipation screening for heart disorders in athletes. (*Level of
Evidence: **B***)

**Gender and Pregnancy**

*Class I*

1.  Pregnant women developing hemodynamically unstable VT or VF should
    be electrically cardioverted or defibrillated. (*Level of Evidence:
    **B***) (See Section above titled \"Acute Management of Specific
    Arrhythmias\".)

2.  In pregnant women with the LQTS who have had symptoms, it is
    beneficial to continue beta-blocker medications throughout pregnancy
    and afterward, unless there are definite contraindications. (*Level
    of Evidence: **C***)

**Elderly Patients**

*Class I*

1.  Elderly patients with ventricular arrhythmias should generally be
    treated in the same manner as younger individuals. (*Level of
    Evidence: **A***)

2.  The dosing and titration schedule of antiarrhythmic drugs prescribed
    to elderly patients should be adjusted to the altered
    pharmacokinetics of such patients. (*Level of Evidence: **C***)

*Class III*

Elderly patients with projected life expectancy less than 1 year due to
major comorbidities should not receive ICD therapy. (*Level of Evidence:
**C***)

**Pediatric Patients**

*Class I*

1.  An ICD should be implanted in pediatric survivors of a cardiac
    arrest when a thorough search for a correctable cause is negative
    and the patients are receiving optimal medical therapy and have
    reasonable expectation of survival with a good functional status for
    more than 1 year. (*Level of Evidence: **C***)

2.  Hemodynamic and EP evaluation should be performed in the young
    patient with symptomatic, sustained VT. (*Level of Evidence: **C***)

3.  ICD therapy in conjunction with pharmacological therapy is indicated
    for high-risk pediatric patients with a genetic basis (ion channel
    defects or cardiomyopathy) for either SCD or sustained ventricular
    arrhythmias. The decision to implant an ICD in a child must consider
    the risk of SCD associated with the disease, the potential
    equivalent benefit of medical therapy, as well as risk of device
    malfunction, infection, or lead failure and that there is reasonable
    expectation of survival with a good functional status for more than
    1 year. (*Level of Evidence: **C***)

*Class IIa*

1.  ICD therapy is reasonable for pediatric patients with spontaneous
    sustained ventricular arrhythmias associated with impaired (LVEF of
    35% or less) ventricular function who are receiving chronic optimal
    medical therapy and who have reasonable expectation of survival with
    a good functional status for more than 1 year. (*Level of Evidence:
    **B***)

2.  Ablation can be useful in pediatric patients with symptomatic
    outflow tract or septal VT that is drug resistant, when the patient
    is drug intolerant or wishes not to take drugs. (*Level of Evidence:
    **C***)

*Class III*

1.  Pharmacological treatment of isolated PVCs in pediatric patients is
    not recommended. (*Level of Evidence: **C***)

2.  Digoxin or verapamil should not be used for treatment of sustained
    tachycardia in infants when VT has not been excluded as a potential
    diagnosis. (*Level of Evidence: **C***)

3.  Ablation is not indicated in young patients with asymptomatic NSVT
    and normal ventricular function. (*Level of Evidence: **C***)

**Patients With Implantable Cardioverter-Defibrillators**

*Class I*

1.  Patients with implanted ICDs should receive regular follow-up and
    analysis of the device status. (*Level of Evidence: **C***)

2.  Implanted ICDs should be programmed to obtain optimal sensitivity
    and specificity. (*Level of Evidence: **C***)

3.  Measures should be undertaken to minimize the risk of inappropriate
    ICD therapies. (*Level of Evidence: **C***)

4.  Patients with implanted ICDs who present with incessant VT should be
    hospitalized for management. (*Level of Evidence: **C***)

Class IIa

1.  Catheter ablation can be useful for patients with implanted ICDs who
    experience incessant or frequently recurring VT. (*Level of
    Evidence: **B***)

2.  In patients experiencing inappropriate ICD therapy, EP evaluation
    can be useful for diagnostic and therapeutic purposes. (*Level of
    Evidence: **C***)

**Digitalis Toxicity**

*Class I*

An antidigitalis antibody is recommended for patients who present with
sustained ventricular arrhythmias, advanced AV block, and/or asystole
that are considered due to digitalis toxicity. (*Level of Evidence:
**A***)

*Class IIa*

1.  Patients taking digitalis who present with mild cardiac toxicity
    (e.g., isolated ectopic beats only) can be managed effectively with
    recognition, continuous monitoring of cardiac rhythm, withdrawal of
    digitalis, restoration of normal electrolyte levels (including serum
    potassium greater than 4 mM/L), and oxygenation. (*Level of
    Evidence: **C***)

2.  Magnesium or pacing is reasonable for patients who take digitalis
    and present with severe toxicity (sustained ventricular arrhythmias,
    advanced AV block, and/or asystole). (*Level of Evidence: **C***)

*Class IIb*

Dialysis for the management of hyperkalemia may be considered for
patients who take digitalis and present with severe toxicity (sustained
ventricular arrhythmias; advanced AV block, and/or asystole). (*Level of
Evidence: **C***)

*Class III*

Management by lidocaine or phenytoin is not recommended for patients
taking digitalis and who present with severe toxicity (sustained
ventricular arrhythmias, advanced AV block, and/or asystole). (*Level of
Evidence: **C***)

**Drug-Induced Long QT Syndrome**

*Class I*

In patients with drug-induced LQTS, removal of the offending agent is
indicated. (*Level of Evidence: **A***)

*Class IIa*

1.  Management with intravenous magnesium sulfate is reasonable for
    patients who take QT-prolonging drugs and present with few episodes
    of torsades de pointes in which the QT remains long. (*Level of
    Evidence: **B***)

2.  Atrial or ventricular pacing or isoproterenol is reasonable for
    patients taking QT-prolonging drugs who present with recurrent
    torsades de pointes. (*Level of Evidence: **B***)

*Class IIb*

Potassium ion repletion to 4.5 to 5 mmol/L may be reasonable for
patients who take QT-prolonging drugs and present with few episodes of
torsades de pointes in whom the QT remains long. (*Level of Evidence:
**C***)

**Sodium Channel Blocker--Related Toxicity**

*Class I*

In patients with sodium channel blocker--related toxicity, removal of
the offending agent is indicated. (*Level of Evidence: **A***)

*Class IIa*

1.  Stopping the drug, reprogramming the pacemaker or repositioning
    leads can be useful in patients taking sodium channel blockers who
    present with elevated defibrillation thresholds or pacing
    requirement. (*Level of Evidence: **C***)

2.  In patients taking sodium channel blockers who present with atrial
    flutter with 1:1 AV conduction, withdrawal of the offending agent is
    reasonable. If the drug needs to be continued, additional A-V nodal
    blockade with diltiazem, verapamil, or beta blocker or atrial
    flutter ablation can be effective. (*Level of Evidence: **C***)

*Class IIb*

Administration of a beta blocker and a sodium bolus may be considered
for patients taking sodium channel blockers if the tachycardia becomes
more frequent or more difficult to cardiovert. (*Level of Evidence:
**C***)

**Other Drug-Induced Toxicity**

*Class I*

1.  High intermittent doses and cumulative doses exceeding the
    recommended levels should be avoided in patients receiving
    anthracyclines such as doxorubicin. (*Level of Evidence: **B***)

2.  All patients receiving 5-fluorouracil therapy should receive close
    supervision and immediate discontinuation of the infusion if
    symptoms or signs of myocardial ischemia occur. Further treatment
    with 5-fluorouracil must be avoided in these individuals. (*Level of
    Evidence: **C***)

3.  Patients with known cardiac disease should have a full cardiac
    assessment including echocardiography, which should be undertaken
    prior to use of anthracyclines such as doxorubicin, and regular
    long-term follow-up should be considered. (*Level of Evidence:
    **C***)

**[Definitions]{.underline}**:

**Levels of Evidence**

-   **Level of Evidence A**: Data derived from multiple randomized
    clinical trials or meta-analyses.

-   **Level of Evidence B**: Data derived from a single randomized
    trial, or nonrandomized studies.

-   **Level of Evidence C**: Only consensus opinion of experts, case
    studies, or standard-of-care.

**Classification of Recommendations**

-   **Class I**: Conditions for which there is evidence and/or general
    agreement that a given procedure/treatment is beneficial, useful,
    and effective.

-   **Class II**: Conditions for which there is conflicting evidence
    and/or a divergence of opinion about the usefulness/efficacy of a
    procedure or treatment.

    -   **Class IIa**: Weight of evidence/opinion is in favor of
        usefulness/efficacy.

    -   **Class IIb**: Usefulness/efficacy is less well established by
        evidence/opinion.

-   **Class III**: Conditions for which there is evidence and/or general
    agreement that a procedure/treatment is not useful or effective and
    in some cases may be harmful.

#### CLINICAL ALGORITHM(S)

One clinical algorithm is provided in the original guideline document:
\"Advanced Cardiac Life Support Pulseless Arrest Algorithm.\"

### EVIDENCE SUPPORTING THE RECOMMENDATIONS

#### TYPE OF EVIDENCE SUPPORTING THE RECOMMENDATIONS

The recommendations are evidence based and derived primarily from
published data. The weight of evidence is given for each recommendation
(see the \"Major Recommendations\" field).

### BENEFITS/HARMS OF IMPLEMENTING THE GUIDELINE RECOMMENDATIONS

#### POTENTIAL BENEFITS

Effective management of patients with ventricular arrhythmias and the
prevention of sudden cardiac death

#### POTENTIAL HARMS

-   Exercise testing in patients with life-threatening ventricular
    arrhythmias may be associated with an incidence of arrhythmias
    requiring cardioversion, intravenous drugs, or resuscitation.

-   Side effects of pharmacologic agents

    -   The use of antiarrhythmic agents may predispose the patient to
        proarrhythmic complications that might pose significant threats
        to life.

    -   Chronic administration of amiodarone is associated with complex
        drug interactions and a host of adverse side effects involving
        the lung, liver, thyroid, and skin. As a general rule, the
        longer the therapy and the higher dose of amiodarone, the
        greater is the likelihood that adverse side effects will require
        discontinuance of the drug. Sotalol, like amiodarone, is
        effective in suppressing ventricular arrhythmias, but it has
        greater proarrhythmic effects and has not been shown to provide
        a clear increase in survival

    -   Intravenous procainamide can cause transient hypotension

-   Problems associated with implantable cardioverter defibrillator
    (ICD) therapy include inappropriate shock discharge mostly for
    atrial fibrillation (AF) with rapid ventricular response,
    defibrillator storm with appropriate recurrent ICD discharge for
    recurrent ventricular tachyarrhythmias or inappropriate discharge
    for a multiplicity of reasons, infections related to device
    implantation, and exacerbation of HF when a high percentage of the
    heartbeats are paced from the right ventricle (RV) apex, especially
    when ventricular function is already compromised. Device failure may
    also rarely occur.

### CONTRAINDICATIONS

#### CONTRAINDICATIONS

-   Sotalol should be avoided in patients with severely depressed left
    ventricular function or significant heart failure.

-   Presentation with frequently recurring torsades de pointes in
    patients with congenital long QT syndrome (LQTS) is unusual. In this
    setting, catecholamines should be avoided.

-   All patients with LQTS should avoid drugs known to prolong the QT
    interval and those that deplete potassium and magnesium.

-   Contraindications to exercise testing can be found in Table 1 of the
    \"American College of Cardiology (ACC)/American Heart Association
    (AHA) 2002 Guideline Update for Exercise Testing.\" (See
    \"Availability of Companion Documents\" field in this summary.)

### QUALIFYING STATEMENTS

#### QUALIFYING STATEMENTS

-   These practice guidelines are intended to assist health care
    providers in clinical decision making by describing a range of
    generally acceptable approaches for the diagnosis and management of
    specific diseases or conditions. These guidelines attempt to define
    practices that meet the needs of most patients in most
    circumstances. These guideline recommendations reflect a consensus
    of expert opinion after a thorough review of the available, current
    scientific evidence and are intended to improve patient care. If
    these guidelines are used as the basis for regulatory/payer
    decisions, the ultimate goal is quality of care and serving the
    patient\'s best interests. The ultimate judgment regarding care of a
    particular patient must be made by the health care provider and the
    patient in light of all of the circumstances presented by that
    patient. There are circumstances in which deviations from these
    guidelines are appropriate.

-   It is important to note that experts can review the same data and
    arrive at different interpretations. Attempting to homogenize
    heterogeneous trials invariably leads to varying interpretations of
    the trial data. Furthermore, differences between the United States
    and Europe may modulate how recommendations are implemented.
    Guidelines are composed of recommendations on the basis of the best
    available medical science; however, implementation of these
    recommendations will be affected by the financial, cultural, and
    societal differences between individual countries.

### IMPLEMENTATION OF THE GUIDELINE

#### DESCRIPTION OF IMPLEMENTATION STRATEGY

An implementation strategy was not provided.

#### IMPLEMENTATION TOOLS

Clinical Algorithm\
Personal Digital Assistant (PDA) Downloads\
Pocket Guide/Reference Cards\
Quick Reference Guides/Physician Guides

For information about
[availability](#identifying-information-and-availability), see the
\"Availability of Companion Documents\" and \"Patient Resources\" fields
below.

### INSTITUTE OF MEDICINE (IOM) NATIONAL HEALTHCARE QUALITY REPORT CATEGORIES

#### IOM CARE NEED

Living with Illness

#### IOM DOMAIN

Effectiveness

### IDENTIFYING INFORMATION AND AVAILABILITY

#### BIBLIOGRAPHIC SOURCE(S)

European Heart Rhythm Association, Heart Rhythm Society, Zipes DP, Camm
AJ, Borggrefe M, Buxton AE, Chaitman B, Fromer M, Gregoratos G, Klein G,
Moss AJ, Myerburg RJ, Priori SG, Quinones MA, Roden DM, Silka MJ, Tracy
C, Smith SC Jr, Jacobs AK, Adams CD, Antman EM, Anderson JL, Hunt SA,
Halperin JL, Nishimura R, Ornato JP, Page RL, Riegel B, Priori SG, Blanc
JJ, Budaj A, Camm AJ, Dean V, Deckers JW, Despres C, Dickstein K,
Lekakis J, McGregor K, Metra M, Morais J, Osterspey A, Tamargo JL,
Zamorano JL, American College of Cardiology, American Heart Association
Task Force, European Society of Cardiology Committee for Practice
Guidelines. ACC/AHA/ESC 2006 guidelines for management of patients with
ventricular arrhythmias and the prevention of sudden cardiac death: a
report of the American College of Cardiology/American Heart Association
Task Force and the European Society \[trunc\]. J Am Coll Cardiol 2006
Sep 5;48(5):e247-346. \[1085 references\]
[PubMed](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16949478)

#### ADAPTATION

Not applicable: The guideline was not adapted from another source.

#### DATE RELEASED

2006 Sep 5

#### GUIDELINE DEVELOPER(S)

American College of Cardiology Foundation - Medical Specialty Society\
American Heart Association - Professional Association\
European Heart Rhythm Association - Professional Association\
European Society of Cardiology - Medical Specialty Society\
Heart Rhythm Society - Professional Association

#### SOURCE(S) OF FUNDING

American College of Cardiology Foundation\
American Heart Association\
European Society of Cardiology

#### GUIDELINE COMMITTEE

American College of Cardiology/American Heart Association Task Force

European Society of Cardiology Committee for Practice Guidelines

Writing Committee to Develop Guidelines for Management of Patients With
Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death

#### COMPOSITION OF GROUP THAT AUTHORED THE GUIDELINE

*Writing Committee Members*: Douglas P. Zipes, MD, MACC, FAHA, FESC,
*Co-Chair*; A. John Camm, MD, FACC, FAHA, FESC, *Co-Chair*; Martin
Borggrefe, MD, FESC; Alfred E. Buxton, MD, FACC, FAHA; Bernard Chaitman,
MD, FACC, FAHA; Martin Fromer, MD; Gabriel Gregoratos, MD, FACC, FAHA;
George Klein, MD, FACC; Arthur J. Moss, MD, FACC, FAHA†; Robert J.
Myerburg, MD, FACC, FAHA; Silvia G. Priori, MD, PHD, FESC\*; Miguel A.
Quinones, MD, FACC; Dan M. Roden, MD, CM, FACC, FAHA; Michael J. Silka,
MD, FACC, FAHA; Cynthia Tracy, MD, FACC, FAHA

\*European Heart Rhythm Association Official Representative

†Heart Rhythm Society Official Representative

*ACC/AHA Task Force Members*: Sidney C. Smith, JR, MD, FACC, FAHA, FESC,
*Chair*; Alice K. Jacobs, MD, FACC, FAHA, *Vice-Chair*; Cynthia D.
Adams, MSN, APRN-BC, FAHA; Elliott M. Antman, MD, FACC, FAHA‡; Jeffrey
L. Anderson, MD, FACC, FAHA; Sharon A. Hunt, MD, FACC, FAHA; Jonathan L.
Halperin, MD, FACC, FAHA; Rick Nishimura, MD, FACC, FAHA; Joseph P.
Ornato, MD, FACC, FAHA; Richard L. Page, MD, FACC, FAHA; Barbara Riegel,
DNSC, RN, FAHA

‡Immediate Past Chair

*ESC Committee for Practice Guidelines*: Silvia G. Priori, MD, PHD,
FESC, *Chair*; Jean-Jacques Blanc, MD, FESC, France; Andrzej Budaj, MD,
FESC, Poland; A. John Camm, MD, FESC, FACC, FAHA, United Kingdom;
Veronica Dean, France; Jaap W. Deckers, MD, FESC, The Netherlands;
Catherine Despres, France; Kenneth Dickstein, MD, PHD, FESC, Norway;
John Lekakis, MD, FESC, Greece; Keith McGregor, PHD, France; Marco
Metra, MD, Italy; Joao Morais, MD, FESC, Portugal; Ady Osterspey, MD,
Germany; Juan Luis Tamargo, MD, FESC, Spain; José Luis Zamorano, MD,
FESC, Spain

#### FINANCIAL DISCLOSURES/CONFLICTS OF INTEREST

The American College of Cardiology(ACC)/American Heart Association (AHA)
Task Force on Practice Guidelines and the ESC Committee for Practice
Guidelines make every effort to avoid any actual, potential, or
perceived conflict of interest that might arise as a result of an
industry relationship or personal interest of the writing committee.
Specifically, all members of the Writing Committee, as well as peer
reviewers of the document, were asked to provide disclosure statements
of all such relationships that might be perceived as real or potential
conflicts of interest. Writing Committee members are also strongly
encouraged to declare a previous relationship with industry that might
be perceived as relevant to guideline development. If a Writing
Committee member develops a new relationship with industry during his or
her tenure, he or she is required to notify guideline staff in writing.
The continued participation of the Writing Committee member will be
reviewed. These statements are reviewed by the parent Task Force,
reported orally to all members of the Writing Committee as changes
occur.

Please see Appendix 1 of the original full-length guideline document for
author relationships with industry and Appendix 2 for peer reviewer
relationships with industry that are pertinent to these guidelines.

#### GUIDELINE STATUS

This is the current release of the guideline.

#### GUIDELINE AVAILABILITY

Electronic copies: Available in Portable Document Format (PDF) from the
[American College of Cardiology (ACC) Web
site](http://www.acc.org/qualityandscience/clinical/pdfs/VASCD_FullText.8.15.06.pdf).

Copies are also available from the [American Heart Association (AHA) Web
site](http://circ.ahajournals.org/cgi/reprint/114/10/e385), and the
[European Society of Cardiology (ESC) Web
site](http://www.escardio.org/guidelines-surveys/esc-guidelines/Pages/ventricular-arrhythmias-and-prevention-sudden-cardiac-death.aspx).

Print copies: Available from the American College of Cardiology,
Resource Center, 9111 Old Georgetown Road, Bethesda, Maryland
20814-1699; (800) 253-4636 (US only).

#### AVAILABILITY OF COMPANION DOCUMENTS

The following is available:

-   ACC/AHA/ESC 2006 guidelines for management of patients with
    ventricular arrhythmias and the prevention of sudden cardiac death -
    executive summary. A report of the American College of
    Cardiology/American Heart Association Task Force and the European
    Society of Cardiology Committee for Practice Guidelines (Writing
    Committee to Develop Guidelines for Management of Patients With
    Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death).
    J Am Coll Cardiol 2006 Sep;48(5):1064-1108. Electronic copies:
    Available from the [American College of Cardiology (ACC) Web
    site](http://www.acc.org/qualityandscience/clinical/pdfs/VASCDExecSum.FINAL.8.14.06.pdf).

-   Consensus reached on new guidelines for management of patients with
    ventricular arrhythmias and the prevention of sudden cardiac death.
    Press release. 2006 Aug 21. 3 p. Available from the [American
    College of Cardiology (ACC) Web
    site](http://www.acc.org/qualityandscience/clinical/pdfs/VASCD Press release_8 21 06.pdf).

Print copies: Available from the American College of Cardiology,
Resource Center, 9111 Old Georgetown Road, Bethesda, Maryland
20814-1699; (800) 253-4636 (US only).

The following are also available:

-   ACC/AHA/ESC 2006 guidelines for management of patients with
    ventricular arrhythmias and the prevention of sudden cardiac death
    -- wallet card. 2006 Sep. 2 p. Electronic copies: Available from the
    [American Heart Association (AHA) Web
    site](http://www.americanheart.org/downloadable/heart/1156944754754VA_Card_FINAL8_28.pdf).

-   Management of patients with ventricular arrhythmias and the
    prevention of sudden cardiac death. Pocket guideline. Electronic
    copies: Available from the [European Society of Cardiology (ESC) Web
    site](http://www.escardio.org/guidelines-surveys/products/pocket/Pages/VASCD.aspx).
    Also available for PDA download from the [ESC Web
    site](http://pocketgram.net/escardio/).

-   ACC/AHA/ESC pocket guideline. Based on the ACC/AHA/ESC 2006
    guidelines. Management of patients with ventricular arrhythmias and
    the prevention of sudden cardiac death. 2006 Sep. 54 p. Electronic
    copies: Available from the [American Heart Association (AHA) Web
    site](http://www.americanheart.org/downloadable/heart/1156943336547VA_PG_FINAL8_28.pdf).

#### PATIENT RESOURCES

None available

#### NGC STATUS

This NGC summary was completed by ECRI on November 22, 2006. The
information was verified by the guideline developer on June 4, 2007.
This summary was updated by ECRI Institute on July 12, 2007 following
the U.S. Food and Drug Administration (FDA) advisory on Troponin-1
Immunoassay.

#### COPYRIGHT STATEMENT

This NGC summary is based on the original guideline, which is subject to
the guideline developer\'s copyright restrictions as follows:

Copyright to the original guideline is owned by the American College of
Cardiology Foundation (ACCF) and the American Heart Association, Inc.
(AHA), and the European Society of Cardiology (ESC). NGC users are free
to download a single copy for personal use. Reproduction without
permission of the ACC/AHA guidelines is prohibited. Permissions requests
should be directed to <copyright_permissions@acc.org>.

### DISCLAIMER

#### NGC DISCLAIMER

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Guidelines represented on the NGC Web site are submitted by guideline
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<http://www.guideline.gov/about/inclusion.aspx> .

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Date Modified: 11/10/2008