Early Feasibility Study of Intramural Needle Ablation for Ablation of Recurrent Ventricular Tachycardia That Has Failed Conventional Radiofrequency Ablation
Phase: NA
Conditions: Ventricular Tachycardia
Sponsor: William Stevenson

1 
 
 
ClinicalTrials.gov title:  Intramural Needle Ablation for Ablation of Recurrent Ventricular 
Tachycardia 
 
NCT01791543 
 
Protocol Document Date: July 16, 2020 
 
 
PI:  William G Stevenson, MD, Professor of Medicine, Vanderbilt University Medical Center

2 
 
Sec. 812.25 Investigational plan. 
 
(a) Purpose 
 
This is an early feasibility study, that is a single-arm, non-randomized study to determine 
the feasibility of using a needle ablation catheter to ablate recurrent ventricular arrhythmia 
that has failed antiarrhythmic drug therapy and standard radiofrequency (RF) catheter 
ablation. 
 
Following ablation patients will be monitored for 6 months. 
The duration of the study is two years. 
Introduction 
 
Catheter ablation has emerged as a first line therapy for many supraventricular 
tachycardias. Ablation for ventricular tachycardias has remained more challenging. In the 
largest multicenter observational trial of irrigated RF ablation for VT after myocardial 
infarction, at least one VT remained inducible in 43% of patients; 47% had recurrent VT 
meeting the study endpoint during the initial 6 months of follow-up.1 The one year 
mortality was 18% and recurrence of VT was associated with a 3 fold increase in mortality. 
One of the important reasons for failure of ablation is inability to adequately damage the 
arrhythmia substrate. Standard catheter ablation approaches the ventricles through the 
vasculature, reaching the endocardial surface. Failure of RF lesions created with present 
technology to reach some intramural or epicardial circuits contributes to ablation failures. 
A percutaneous epicardial approach allows epicardial ablation for some patients, but is not 
possible without surgery in patients who have pericardial adhesions from prior cardiac 
surgery. Once epicardial access is achieved, ablation is sometimes limited by the presence 
of epicardial fat, or overlying coronary arteries that protect the ablation target. Options for 
patients who fail ablation are limited. Transcoronary ethanol ablation is considered at 
some centers, but limited by coronary anatomy. Intraoperative surgical ablation can be 
considered for some patients, but has significant morbidity, and technologies for operative 
mapping have not kept up with percutaneous techniques, and few centers maintain a 
surgical ablation program.  Use of left ventricular support devices is problematic  in 
patients with recurrent VT due to the fall in venous return that occurs with VT in the 
absence of right heart support. In some cases the only option is cardiac transplantation. 
Application of radiofrequency ablation current through a needle inserted into the 
myocardium offers the potential for ablation of VTs that have an origin deep to the 
endocardium, that are not adequately treated by other means. 2 

3 
 
(b) Protocol 
 
This is a non-randomized early feasibility study. Patients with recurrent sustained or 
incessant ventricular arrhythmia who have failed antiarrhythmic drug therapy and prior 
catheter ablation will be offered participation. Ablation will be performed with the needle 
ablation catheter. Patients will be monitored in hospital for complications and during 6 
months follow-up. 
 
Screening Procedures 
Patients referred to Vanderbilt University Medical Center or Brigham and Women’s 
hospital for catheter ablation of sustained or incessant ventricular arrhythmia or 
symptomatic monomorphic ventricular tachycardia and who have failed attempted 
radiofrequency catheter ablation will be offered participation in this study. 
 
Informed Consent 
The investigator or designated member of the research team will approach the patient to 
obtain written informed consent. The background of the proposed study and the potential 
benefits and risks of the procedures and study will be explained to the subject. The patient 
must sign the consent form prior to enrollment. 
 
Patients who are consented but in whom the needle catheter is not inserted, and 
consequently are not treated with the needle ablation catheter will be exited from the 
study and not included in the final analysis. 
 
 
Patient Selection – Inclusion Criteria 
Candidates for the study must meet ALL of the following criteria: 
 
1. 
Monomorphic ventricular tachycardia or incessant ventricular arrhythmia (defined 
as > 20% of beats due to ventricular arrhythmia including unifocal PVCs, couplets, 
Nonsustained VT) that is causing a decline in LV ejection fraction to less than 50% 
that meets the following criteria: 
a. Ventricular arrhythmia is recurrent and symptomatic 
b. prior antiarrhythmic drug therapy has failed due to recurrent ventricular 
arrhythmia, toxicity, or intolerance 
2. 
Age 18 or older 
3. 
Left ventricular ejection fraction > 10% as estimated by echocardiography or 
contrast ventriculography within the previous 90 days. 
4. 
Failed prior VT or PVC ablation due to spontaneous recurrence of sustained VT or 
frequent clinical PVCs . 

4 
 
5. 
Able and willing to comply with all pre-, post-, and follow-up testing and 
requirements. 
6. 
Signed Informed Consent 
 
Exclusion Criteria 
 
1. 
Patients with idiopathic VT defined as VT that originates from a region without 
evidence of scar detected by MRI or voltage mapping in a patient without other evidence of 
heart disease that is not causing significant depression of ventricular function. 
2. 
Definite protruding LV ventricular thrombus on pre-ablation echocardiography 
when LV ablation is required. 
3. 
Thrombotic myocardial infarction within the preceding two (2) months. 
4. 
Other disease process that is likely to limit survival to less than 12 months. 
5. 
Class IV heart failure, unless heart failure is due to frequent or incessant VT. 
6. 
Contraindication to heparin. 
7. 
Allergy to radiographic contrast dye. 
8. 
Severe aortic stenosis 
9. 
Severe mitral regurgitation with a flail mitral valve leaflet. 
10. 
Significant congenital anomaly or medical problem that in the opinion of the 
principal investigator would preclude enrollment into the study. 
11. 
Enrolled in another investigational study evaluating a drug or device. 
12. 
Unstable angina that is not due to frequent or incessant VT. 
13. 
Women who are pregnant. 
14. 
Thrombocytopenia (platelet count < 50,000) or coagulopathy. 
15. 
Acute non-cardiovascular illness or systemic infection. 
16. 
Cardiogenic shock unless it is due to incessant VT 
Study Endpoints 
Primary Endpoints 
a. Efficacy endpoint for VT: control of VT as defined by: freedom from 
hospitalization for recurrent VT during the 6 months following ablation. 
b. Safety endpoint: absence of all serious adverse events that are listed below that 
are potentially device related and occur within 30 days of the ablation procedure (see 
below) 
c. Efficacy endpoint for ventricular arrhythmia causing significant ventricular 
dysfunction: decrease in ambient ventricular arrhythmia to < 5000 ventricular beats 
daily 
 
 
 
 
 

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Secondary Endpoints 
a. Acute Procedural Success defined as termination of at least one clinical or 
presumptive clinical monomorphic VT by RF ablation or rendering that VT no 
longer inducible. It is recognized that this secondary efficacy endpoint will not be 
assessed in all patients because VT induction will not be attempted in patients in 
whom, in the judgment of the investigator, attempted VT induction imposes 
unwarranted risk of hemodynamic deterioration. A clinical or presumptive clinical 
VT is one that has been documented to occur spontaneously, or is within 20 ms in 
cycle length of a VT that has been documented to occur spontaneously. 
 
 
Definition of serious adverse events: 
 
1. stroke 
2. pericardial effusion causing cardiac tamponade or requiring drainage. 
3. myocardial infarction due to coronary occlusion 
4. Peripheral arterial thromboembolism 
5. cardiogenic shock not due to ventricular tachycardia 
6. vascular bleeding or injury requiring transfusion or surgical intervention for vascular 
repair or to stop bleeding. 
7. valve injury: new moderate or severe aortic regurgitation, new mitral valve disruption 
with severe mitral regurgitation 
8. Heart failure exacerbation not due to uncontrollable ventricular tachycardia, defined as 
requiring hospitalization for > 24 hours 
9. Death 
10. Sepsis 
Other adverse events (not necessarily device related or serious) that will be collected post 
procedure: 
 
1. syncope 
2. chest pain 
3. new hyperthyroidism 
4. new hypothyroidism 
5. urinary tract infection 
6. pneumonia 
7. drug allergic reaction 
Description of Treatments 
Pre-Procedure Assessments 

6 
 
The following pre-procedure assessments will be performed for a subject undergoing 
treatment prior to the study procedure: 
- 
Baseline medical history (including arrhythmia symptoms and hospitalizations) 
- 
Laboratory values (creatinine, CBC, PT/PTT, electrolytes, and pregnancy test, if 
applicable) 
- 
ICD interrogation (if applicable) 
- 
Transthoracic echocardiogram within 3 weeks and after the latest non-study 
catheter ablation procedure. 
- 
If the subject has had an echo within 90 days to evaluate LV ejection fraction and 
valve function, Intra cardiac echocardiogram (ICE) would be an option to evaluate 
for left ventricular thrombus prior to deployment of any catheter in the left 
ventricle. 
- 
 24-48 hour holter monitor since last ablation procedure to quantify arrhythmia 
burden in subjects with ventricular arrhythmia/PVC induced cardiomyopathy 
 
 
Electrophysiologic Study 
 
After written informed consent has been obtained eligible patients will be brought to the 
cardiac electrophysiology laboratory in the post-absorptive state. Hemodynamic 
monitoring and conscious sedation and general anesthesia will be implemented according 
to hospital standards. Urinary bladder catheter may be placed to allow for monitoring of 
urine output and fluid balance, especially for subjects with a history of congestive heart 
failure, or who are hemodynamically unstable, or have an ejection fraction of <40%. 
Subjects will have continuous monitoring of arterial pressure during the mapping and 
ablation procedure. Arterial and venous hemostatic sheaths will be inserted, though which 
one or more diagnostic electrode catheters will be introduced at the discretion of the 
investigator, to confirm the diagnosis and facilitate mapping as per usual practice. If VT is 
not incessant, programmed cardiac stimulation will be performed to confirm the diagnosis 
of ventricular tachycardia. Atrial pacing and recording may be performed at the discretion 
of the operator. 
 
Programmed ventricular stimulation for assessing VT inducibility: 
 
Ventricular stimulation will be performed from the right ventricular apex and/or right 
ventricular outflow tract at > twice threshold stimulus strength. Programmed stimulation 
at two drive cycle lengths (typically 600 and 400 ms) with up to triple ventricular 
extrastimuli and burst ventricular pacing will be performed from two right ventricular 
sites. Burst pacing to a cycle length of 250 ms or loss of 1:1 capture can be performed. Left 
ventricular pacing may be used if RV pacing is ineffective. The endpoint of stimulation is 

7 
 
the final stimulus reaching the refractory period, or a coupling interval of 180 ms or 
initiation of sustained ventricular tachycardia or ventricular fibrillation. The endpoint of 
the procedure is absence of inducible sustained monomorphic VTs that were targeted for 
ablation or absence of adequate target sites. 
 
Initial Mapping to Identify the Target Region 
 
Once the diagnosis of VT has been confirmed an intracardiac ultrasound catheter will be 
inserted for monitoring ventricular function, catheter location, and pericardial effusion. 
Initial ventricular mapping will then be performed with a standard (non-needle) ablation 
(Biosense Webster, Inc Thermocool, Navistar, EZ Steer, or Surround Flow catheters) 
catheter for identification of the likely VT origin and to create a voltage map of the region to 
define potential scar using the CARTO electroanatomic mapping system (Biosense Webster, 
Inc). The likely origin of VT will be defined based on any of activation: sequence mapping, 
entrainment mapping, or pace-mapping as per usual laboratory practice. 
 
For left ventricular mapping (and ablation), systemic anticoagulation with heparin should 
be administered with activated clotting time (ACT) checked throughout the procedure at 
the investigators discretion or per customary policy to maintain ACTs of 250-350 seconds. 
For left ventricular access transeptal or retrograde aortic approaches can be used. 
 
If long sheaths are used to access the LV (e.g. for transeptal approach) these will be 
continuously irrigated with heparinized saline. 
 
Mapping and Ablation with the Needle Catheter 
 
1. The needle length will be set to 7 to 8 mm initially. If this is subsequently ineffective and   
there has been no evidence of myocardial perforation with that needle length, the length 
can be increased to 10 mm for septal or LV applications. 
 
2. Set the RF generator to temperature control mode. 
 
3. Start continuous irrigation with room temperature, heparinized saline (1 u 
heparin/1ml Saline) at a flow rate of 1 ml/min during mapping. 
 
With a second irrigation pump start continuous irrigation with heparinized saline to the 
central lumen of the catheter that irrigates the gap between the needle at a flow rate of 
1/ml/min. throughout the procedure. 

8 
 
4. At the potential target site the needle is inserted into the tissue. The catheter stopcock 
is set to manual injection, and 1 mL of 50% heparinized saline (1000 u/L) and isovue 
contrast is injected through the needle. The stopcock is set to the Cool flow pump and the 
pump irrigation flow rate is set to 2 ml/min. After 30- 60 seconds RF application can be 
initiated. The 2 ml/min flow rate is continued until 2-5 seconds after the termination of RF 
energy application. 
 
5. Prior to RF initiation the position of the needle in the tissue is assessed from evidence of 
capture during pacing on the needle and / or appearance of the contrast in the tissue. If the 
site is felt to be potentially related to the arrhythmia and there is no evidence that the 
needle has reached the pericardial space then ablation can be performed. Otherwise, the 
needle will be retracted back into the catheter and catheter repositioned for additional 
mapping or better deployment. 
 
The length of the needle is set to be shorter than myocardial thickness as assessed from ICE 
to reduce the chance that the needle can reach the pericardial space. Evidence that the 
needle has potentially reached the pericardial space includes staining of the pericardial 
space by injected contrast, or development of a new pericardial effusion or increase in 
previous pericardial effusion assessed from ultrasound imaging. If this occurs the needle 
the needle will be retracted into the catheter. Intracardiac ultrasound monitoring of the 
pericardial space will be used to detect early formation of an increasing pericardial 
effusion. If an increasing pericardial effusion is observed, heparin will be reversed and all 
catheters removed from the left heart. Preparations for pericardiocentesis will be 
implemented and performed if the effusion continues to increase or there is any evidence 
of impending pericardial tamponade by intracardiac echocardiography, or hemodynamic 
deterioration. 
 
If contrast appears in the pericardium, the needle will be withdrawn and close monitoring 
for pericardial effusion continued with intracardiac ultrasound for the duration of the 
procedure. An increasing pericardial effusion will be indication to reverse anticoagulation 
and remove all catheters from the left heart. 
 
6.  The initial ablation temperature should be 60C and maximum power 35 Watts. If 
needed, power can be increased (to maximum 50 W). The duration of each RF application 
should target is 60 seconds and will not exceed 120 seconds. RF ablation can be 
interrupted early if there is evidence of inefficacy, such as failure of VT to terminate after 
10 to 30 seconds of RF when ablation is done during VT, or if temperature does not 
increase as expected, indicating possible inadequate needle deployment, or if 
dislodgement of the needle is suspected by the operator. 

9 
 
7.  If, for any ablation, the impedance rises 5- 10 ohms or more during RF application, the 
RF application should be terminated immediately. The catheter should be removed and 
any visible coagulum cleaned, if present. The flow of irrigation throughout the catheter 
should be verified before re-inserting the catheter. 
 
8.  Ablation during sinus rhythm - When RF energy is delivered during sinus rhythm, 
power levels up to 50 Watts will be delivered for each RF application for up to 2 minutes, 
at the Investigator’s discretion. 
 
9.  While it is recommended that continuous RF application should not exceed 120 
seconds, the Investigator has the option of terminating RF current delivery at any time 
and at any given power level as dictated by the patient’s clinical condition. For every 
application of RF energy, the maximum power, maximum temperature, maximum 
impedance and duration of burn will be monitored continuously and recorded either on 
optical disc or paper. 
 
10. After RF termination electrograms are recorded from the needle and pacing may 
be performed through the needle after ablation to assess capture if desired. The 
needle is then retracted back into the catheter and the irrigation rate reduced to 1 
ml/minute. 
 
11. Verification of the effects of the ablation procedure on inducible VTs using 
programmed electrical stimulation may be performed based on the subject’s 
hemodynamic stability, at the Investigator’s discretion. Using the same stimulation 
protocol as prior to ablation (above). If VT remains inducible, the mapping procedure is 
repeated at adjacent sites.  Once an RF lesion terminates or prevents VT, two additional 
lesions can be applied at closely adjacent sites if desired, provided that intracardiac 
ultrasound does not show evidence of new pericardial effusion. 
 
If defibrillation is required to terminate VT while the needle is deployed, the needle will 
be retracted before the defibrillator is discharged. 
 
12. At the end of the procedure ultrasound images will be assessed for the presence 
of pericardial effusion. 
 
Procedure endpoints: 
 
1. All targeted VTs are no longer inducible or the targeted ventricular arrhythmia is no 
longer present 

10 
 
2. Ablation has been performed at the target region, and programmed stimulation to 
assess inducibility is not desired because of concern that it may precipitate hemodynamic 
deterioration 
3. There are no target sites identifiable 
 
 
Repeat Ablation Procedures 
Repeat ablation procedures will be at the discretion of the investigator and will follow the 
standard of care. 
 
5.6 
Post-Procedure Assessments 
After the procedure, management of the arterial sheath and heparin usage will be at the 
discretion of 
the investigator. Prior to discharge, the investigator will assess and record the subject’s 
clinical status and any complications, and complete the following assessments: 
a. CK-MB and Cardiac Troponin will be measured 4 to 8 hours and approximately 
24 hours after the ablation procedure. 
b. Post-procedure ICD interrogation 
c. Post-procedure echocardiogram will be obtained prior to hospital discharge 
 
Drug Management 
Drug management during the follow-up period will be at the discretion of the investigator 
and treating physicians. Anticoagulation with aspirin, warfarin, or direct acting oral 
anticoagulation is required for a minimum of three (3) months. Warfarin or direct acting 
oral anticoagulation is recommended for subjects who receive left ventricular RF ablation 
lesions over large areas such that the lesions are separated by more than 3 cm. 
 
Patients will be observed in hospital for a minimum of 24 hours after the procedure with 
continuous ECG telemetry monitoring. 
 
 
Follow-up Visits 
Follow-up visits will be performed at Brigham and Women’s Hospital, unless travel 
imposes a hardship on the patient, in which case the patient’s 
cardiologist/electrophysiologist can perform the follow-up visit and send the required 
information to the investigator. Each follow-up visit will include assessment of adverse 
events, antiarrhythmic drug use, and anticoagulant use. 
 
Follow-up visit one will be between 3 and 6 weeks after ablation with: 
• 
ICD interrogation (if the patient has an ICD) 

11 
 
• 
Medical history since the last visit 
• 
For patients with ventricular arrhythmia that is not VT that was producing 
depressed ventricular function, a holter will be obtained between 3 and 6 
weeks after ablation. 
 
Follow-up visit two will be between 5 and 7 months post ablation. 
This visit includes the following: 
• 
Transthoracic echocardiogram 
• 
ICD interrogation 
• 
Medical history since the last visit 
 
 
 
(c) Risk Analysis: 
 
As discussed in the introduction, failed ablation is associated with risks of recurrent VT, 
ICD shocks in patients with ICDs, and mortality associated with recurrent VT.1 
 
Possible increased risks of this investigation include the following: 
Increased risk of perforation or tamponade 
Increased risk of thromboembolism 
Increased risk of myocardial dysfunction 
Increased risk of injury to cardiovascular structures or pericardiac structures 
Increased risk of proarrhythmia 
Risk of contrast allergy 
 
The following precautions and procedures are taken to minimize risks: 
 
Increased risk of perforation or tamponade: Catheter mapping and ablation have a risk of 
cardiac perforation and tamponade that is approximately 1%.3 Inserting the needle itself 
into the myocardium is anticipated to increase the risk of perforation. It is expected that 
the small size of this needle (27 gauge) will be associated with a minimal risk of significant 
pericardial bleeding, based on animal studies. Larger needles are commonly inserted into 
the myocardium during cardiac surgery for “de-airing” the ventricle and do not produce 
significant bleeding. The larger and deeper lesions produced by needle ablation compared 
to standard ablation, however, are anticipated to have an increased risk of cardiac 
perforation and tamponade. Precautions include: assessment of needle position in the 
myocardium based on contrast injection. If the tip of the needle reaches the pericardial 
space, it is anticipated that this will be recognized by contrast injection (the contrast 
dispersing in the pericardium), and the needle will be retracted without application of RF 

12 
 
energy. Intracardiac ultrasound will be employed to monitor for pericardial effusion 
throughout the procedure so that this complication can be promptly detected and treated. 
The investigators are experienced in recognition and treatment of pericardial effusion and 
tamponade. The procedures are performed at Brigham and Women’s hospital with 
immediate availability of cardiac surgery if required for persistent or uncontrollable 
bleeding. 
 
Increased risk of thromboembolism: Catheter mapping and ablation has a known risk of 
thromboembolism that is less than 1%.1, 4-6 Thrombus on the needle catheter has not been 
observed during animal studies. None of the initial 3 patients experienced an embolic 
event. The needle will be irrigated with heparinized saline. For left heart mapping, 
systemic anticoagulation with heparin will be employed. RF application will be promptly 
terminated if impedance increases, which can be an indication of coagulum formation with 
standard RF ablation. 
 
Increased risk of myocardial dysfunction: Greater ablation lesion size is anticipated to 
have greater risk of myocardial damage. Ablation targets will be restricted to regions that 
are felt to cause VT, and which in the majority of patients are areas of scar that do not 
appear to contribute to ventricular function. Gaining control of the arrhythmia in these 
patients is felt to out-weigh the risk of myocardial damage. Hemodynamic monitoring will 
be continuous during the procedure. 
 
Increased risk of damage to cardiovascular structures: valves, blood vessels: This is also a 
known risk with standard catheter ablation. The needle will be kept retracted within the 
shaft of the catheter until deployment into the targeted myocardium. If defibrillation is 
required to terminate VT while the needle is deployed, the needle will be retracted before 
the defibrillator is discharged. Intracardiac ultrasound and fluoroscopy will be used to 
monitor catheter position. The investigators are experienced with catheter mapping. 
 
Increased risk of proarrhythmia: Larger ablation lesions could theoretically increase the 
risk of aggravating arrhythmias. Cardiac rhythm will be continuously monitored during the 
procedure and until hospital discharge. It is anticipated that the majority of patients with 
have implanted defibrillators. Pre-clinical studies have demonstrated that needle ablation 
lesions are homogeneous with sharp border zones; features characteristic of 
radiofrequency ablation lesions which likely contributes to their very low proarrhythmic 
potential.2, 7 
 
Risk of contrast allergy: Patients with a documented contrast allergy are excluded from 
participation. 

13 
 
 
In addition to these risks, there are risks inherent in the electrophysiologic procedure that 
are not specific to the needle ablation. These include: Other potential complications which 
may result from catheter insertion and manipulation as part of the prerequisite 
electrophysiology study and mapping procedure include: Allergic reaction to the local 
anesthetic, sedatives, heparin, protamine, or other agents administered during the 
procedure (risk <1%). Arterial or venous injury, including arterial dissection, thrombosis, 
occlusion or hemorrhage at the catheter insertion sites or at other sites along the vessels. 
This may produce hemorrhage, hematoma or ischemic injury to an extremity or major 
organ. Hemorrhage as a result of anticoagulation (risk <0.5%) which may require 
transfusion. Infection, either at the catheter insertion site or systemically, including 
endocarditis and septic emboli (risk <0.5%). This risk can be minimized by using standard 
aseptic technique and, when indicated, by the use of antibiotic agents. 
 
Risks/Discomforts that may be 
increased with needle ablation 
Severity 
Expected Frequency: 
common = 10 – 20 
per 100 
less common = 2 – 9 
per 100; 
rare = 1 per 100 
Damage to other parts of the normal 
electrical conduction system. 
mild to 
moderate 
less common 
Trigger an irregular fast heart rhythm 
mild 
common 
Injury to the heart muscle with bleeding 
into the pericardium (heart sac) 
surrounding the heart. 
severe 
less common 
Injury to the heart valves which are 
located between each of the four heart 
chambers. 
mild to severe 
rare 
Development of blood clots and the 
movement of blood clots, during or after 
the procedure. You will be given an anti 
blood-clotting medication to help stop 
the blood clots from developing. 
moderate to 
severe 
less common 
chest pain 
mild 
common 

14 
 
 
The following risks exist for all ablation 
procedures: 
 
reactions to medication and/or drugs 
that are given during anesthesia (drugs 
used to help a person relax and eliminate 
pain during a procedure), 
mild to severe 
less common 
blood loss 
mild to severe 
less common 
fever 
mild 
less common 
infection 
mild to severe 
less common 
myocardial infarction 
severe 
less common 
stroke 
moderate to 
severe 
less common 
air embolism 
mild to severe 
less common 
pericarditis (pain from inflammation 
around the heart) 
mild 
less common 
bleeding into the groin area causing pain 
and black and blue area 
mild to 
moderate 
common 
damage to an artery in the groin that 
may require surgery (known in medical 
terms as a pseudoaneurysm or AV 
fistula) 
moderate 
less common 
collapsed lung 
severe 
rare 
bleeding or fluid accumulation into the 
lung or space around the lung 
severe 
rare 
congestive heart failure 
moderate 
less common 
low blood pressure 
mild to severe 
less common 
fainting 
mild to 
moderate 
less common 
damage or movement of a defibrillator 
wire that may require surgery 
moderate 
less common 
shocks from an implanted defibrillator 
mild 
less common 
shortness of breath 
mild 
less common 
injury to the nerve to the diaphragm that 
can cause shortness of breath 
moderate 
less common 
blood loss causing a low blood count 
mild to 
moderate 
less common 
skin burns from defibrillator patches or 
the ablation catheter grounding pad 
mild to 
moderate 
less common 
blood in the urine and pain from the 
mild 
less common 

15 
 
 
urinary catheter insertion 
 
rarely, death 
severe 
less common 
 
 
(d) Device Description 
(see Biosense Webster, Inc Master Access File # MAF-1893) 
Authorization letter of June 17, 2016 from Biosense Webster is attached. 
The Biosense Webster Needle Ablation Diagnostic/Ablation Catheter is an 8 F, steerable, 
multi-electrode, irrigated, luminal catheter with three distinct electrodes: a needle 
electrode for RF delivery plus a 4 mm tip electrode and ring electrode which are used for 
mapping, recording and stimulation purposes. The catheter has a unidirectional deflectable 
tip designed to facilitate electrophysiological mapping of the ventricles of the heart and to 
transmit radiofrequency (RF) current to the catheter needle electrode for ablation 
purposes. For ablation, the catheter is used in conjunction with an RF generator and a 
dispersive pad (indifferent electrode). The catheter has a usuable length of 115 mm. 
 
The catheter has a high-torque shaft with a unidirectional deflectable tip section containing 
a single platinum ring electrode. The tip and the ring electrodes are made of platinum- 
iridium. The needle electrode is made of Nitinol. The needle is used to deliver RF current 
from the RF generator to the desired ablation site. 
 
The catheter incorporates one thermocouple temperature sensor located within the distal 
tip of the needle. The RF generator monitors the temperature of the needle thermocouple 
allowing it to use temperature feedback to limit power delivery. 
 
The needle electrode is controlled at the proximal end of the catheter. Pushing the needle 
thumbknob into the injector barrel extends the needle electrode. A locking mechanism 
holds the thumbknob in place once the thumbknob has been pushed down, if the 
thumbknob is not locked and force is removed a spring automatically retracts the needle. 
The needle extends a maximum of 10 mm from the distal portion of the tip electrode. This 
length of the extended needle can be reduced by rotating the thumbknob clockwise. 
 
At the proximal end of the catheter, a fluid input port with a standard Luer fitting 
terminates from the open lumen. This port serves to permit the injection of heparinized 
normal saline to irrigate the needle electrode. During ablation, heparinized normal saline is 
passed through the needle to irrigate and cool the ablation sites as well as the needle 
electrode. An irrigation pump must be used to control the saline irrigation. The port also 
allows the injection of Isovue or a similar contrast agent to verify under fluoroscopy the 
placement of the needle within the myocardium. An additional input port allows irrigation 

16 
 
of the gap surrounding the needle. The gap is irrigated with a second pump to prevent 
blood retrograde flow inside the catheter shaft. 
 
Tip deflection is controlled at the proximal end by a handpiece in which a piston slides; a 
deflection thumbknob on the piston controls piston travel. When the deflection thumbknob 
is pushed forward, the tip is deflected (curved). When the deflection thumbknob is pulled 
back, the tip straightens. The shape of the curve depends on the deflectable tip length. The 
high-torque shaft also allows the plane of the curved tip to be rotated to facilitate accurate 
positioning of the catheter tip at the desired site. 
 
The catheter features single location sensor mounted within the tip of the catheter which 
transmit location information to the CARTO® 3 EP Navigation System. An appropriate 
reference device is required for location reference position purposes. The catheter 
interfaces with an RF Generator via a Catheter Interface Cable. 
 
During mapping the needle is retracted within the catheter and irrigated at a rate of 1 
ml/minute using a continuous flow pump (Cool flow , Biosense Webster, Inc). After 
extension of the needle into the myocardium a hand injection of 1 ml of a 50:50 saline 
contrast mixture is applied to stain the tissue demonstrating needle deployment in the 
tissue, followed by continuous irrigation at 2 ml/minute during RF current application. The 
gap is irrigated continuously with a second irrigation pump at a rate of 1ml/min. 
 
Patient Population and Justification of Risk 
 
Patients will be adults of either gender with symptomatic ventricular tachycardia that is 
either immediately life-threatening or causing ventricular dysfunction and that have failed 
antiarrhythmic drug therapy and prior catheter ablation procedure. In this setting, failure 
to achieve control of the arrhythmia can result in eventual death or need for cardiac 
replacement therapy (e.g. transplantation).1, 5, 6 This patient population has a significant 
mortality.1, 5 In one multicenter study of post-infarction patients who had failed 
antiarrhythmic drug therapy and were undergoing catheter ablation the one year mortality 
was 18%, and recurrent VT, indicating failure of ablation, was associated with a 3 fold 
greater risk of mortality.1 Those who are able to survive with recurrent ventricular 
arrhythmias are often subject to recurrent episodes producing syncope or eliciting ICD 
shocks have reduced quality of life and significant psychological dysfunction.4 8 If needle 
ablation achieves arrhythmia control, these individuals could experience substantial 
improvement in quality of life and survival. 
 
This is an early feasibility trial in 50 patients. The endpoints focus on identifying device 
related complications and showing the possibility of efficacy. Because this patient 

17 
 
population has frequent arrhythmias a successful ablation that controls the arrhythmia 
could be dramatically successful, as has been observed in the small number of patients 
evaluated at QEII Health Sciences Centre in Halifax, Nova Scotia to date. It is anticipated 
that the major complications will be procedure related and evident during or shortly after 
the procedure, prior to hospital discharge. 
 
Data Analysis 
 
The populations baseline characteristics, and procedure characteristics will be described 
with the use of proportions, medians and inter-quartile ranges as appropriate. The 
primary endpoint will be assessed with a Kaplan Meier survival curve. The safety endpoint 
will be reported as the proportion of patients experiencing any adverse event, and each 
adverse event. The secondary endpoint will be reported as the proportion of patients 
meeting that endpoint. 
 
 
(e) Monitoring procedures. 
 
Early Feasibility of Intramural Needle Ablation for Ablation of Recurrent Ventricular 
Tachycardia that has Failed Conventional Radiofrequency Ablation 
 
Applicability 
 
This monitoring plan addresses study-specific issues for monitoring of “Early Feasibility of 
Intramural Needle Ablation for Ablation of Recurrent Ventricular Tachycardia that has 
Failed Conventional Radiofrequency Ablation”. 
 
Study Design 
 
A prospective, non-randomized study will be conducted. A total of 130 subjects with 
recurrent drug/ablation refractory sustained monomorphic ventricular arrhythmia who 
are > 18 years old will be enrolled in this trial. 
 
Investigator and Clinical Site 
 
This study is a physician sponsored IDE with two approved sites. 
 
 
 
 
 
 
 
 

18 
 
William G. Stevenson, M.D. is the Sponsor- Investigator 
Vanderbilt University Medical Center 
Medical Center East 
1215 21st Ave. S. 
Nashville, TN 37232-8802 
 
 
Usha Tedrow, M.D. is the site Primary Investigator 
Brigham and Women’s Hospital 
75 Francis Street 
Boston, MA 02115 
 
 
Study Staff 
 
The study site will have dedicated study coordinators. If the study coordinators are unable 
to attend EP cases, then the investigator performing the case is responsible for study data. 
 
Device Storage and Accountability 
 
The site is responsible for managing investigational device inventory in accordance with 
institution policy and federal regulations. Investigational devices will be kept in a 
designated locked cabinet. Devices will be logged in upon arrival and will be logged out 
when used during a study procedure or expired. Expired catheters will be sent back to the 
manufacturer and when applicable a replacement device will be ordered. Following use, 
investigational devices must be handled according to manufacturer’s specifications. Device 
records will be kept in the regulatory binder under the catheter accountability section. 
Study coordinator will review catheter accountability records to verify appropriate 
documentation of investigational devices. 
 
If a discrepancy is noted during monitoring, immediate corrective action will be taken. The 
discrepancy and corrective action will be documented in study records and reviewed with 
the study staff. 
 
Routine Data Monitoring 
 
Monitoring will be performed by Dr. Bruce Koplan, M.D. and Dr. Melanie Maytin, M.D., every 
6 months or more often if subject enrollment is high. 
 
 
 
 
 
 

19 
 
During monitoring, the Monitor will ensure: 
 
Regulatory and protocol adherence by investigators and study staff. 
Accurate CRF documentation by comparing CRF entries to patient medical records. 
Capture of AE data by reviewing patient medical records and follow-up records. 
Reporting of AE’s to the IRB, manufacturer, and FDA as per study plan and regulations. 
Each case of cardiac tamponade or cardiogenic shock will be reviewed to make a 
determination of whether these events warrant stopping the study. 
The study will be suspended for interim analysis in the event of 3 serious adverse events 
related to the procedure such as need for surgical treatment for tamponade or procedure- 
related death. 
 
Adverse events will be adjudicated by the study Medical Monitors. 
 
Monitoring Reports 
 
Monitoring reports will be completed after every monitoring visit. Any deficiencies and 
corrective actions will be documented and discussed with investigators and study staff. 
Checklist and worksheets will be filed in Monitoring section of regulatory binder. 
 
(f) Labeling. Copies of all labeling for the device. N/A 
 
(g) Consent materials. see attached Consent Form 
 
(h) IRB information. 
 
 
Vanderbilt University Medical Center 
Vanderbilt Institutional Review Board Human Research 
Protection Program 
3319 West End Ave., Suite 600 
Nashville, TN 37203 
Tel: 615-322-2918 
 
Julie Ozier, MHL, CIP - Director 
Human Research Protection Program  
3319 West End Ave., Suite 600 
Nashville, TN 37203 
Tel: 615-322-2918 
 
 
 
 
 
 

20 
 
Brigham and Women’s Hospital 
Partners Human Research Committee 
399 Revolution Drive 
Somerville, MA 02145 
 
Tel: 617-424-4100 Fax: 617-424-4199 
 
Libby Hohmann, M.D.- Director and Chair 
Partners Human Research Committee 
399 Revolution Drive 
Somerville, MA 02145 
Tel: 617-424-4127 
 
 
 
Sec. 812.27 Report of prior investigations. 
 
(a)General. 
Previous Experience with the Device 
Animal Investigations 
The investigations below were performed in the cardiac experimental laboratory at 
Brigham and Women’s hospital and were not conducted under GLP regulations, as they 
were either exploratory or conducted with a limited budget. 
 
Initial in-vivo without Irrigation 
The initial pilot study was performed in 3 swine (32 – 58 kg).2 Ventricular lesions were 
created by extending the needle to its full depth and applying RF current for two minutes, 

21 
 
with manual titration of energy to a needle temperature at or slightly below 90 degrees C. 
These were compared to control lesions created with a 4 mm solid tip electrode. Irrigation 
was not applied to either catheter. A total of 14 needle ablations were created, one could 
not be definitely located. Data from the remaining 13 showed lesions that extended the full 
depth of the needle, but narrow, (only a mean of 4.4+0.1 mm wide), compared to control 
lesions which had a mean diameter of 8.5+2 mm (figure). Mean power for needle ablation 
was only 2 Watts to achieve 90 degrees C.(Stevenson WG, Sapp J, Annual and Final Report 
to CIMIT September 2002). Animals were sacrificed immediately after completion of the 
lesion creation protocol. One animal had cardiac tamponade after perforation of the thin 
LV apex with the needle catheter. A second had a hemopericardium without tamponade at 
examination. Conclusions were that deep lesions could be created, with efficient energy 
application, but lesion diameter was likely insufficient. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
from ref Sapp et al PACE 2004;27:594- 
599.2 
 
In-vitro with Saline Irrigation 
The second set of investigations was performed to determine if saline irrigation of the 
needle during RF application would increase lesions size. In- vitro experiments were 
performed in bovine myocardium in a saline bath.(Stevenson WG, Sapp J, Annual and Final 
Report to CIMIT September 2002). Saline irrigation was applied during RF application and 
a range of powers from 4 to 12 Watts, and duration of applications studied. Tissue 
temperature was recorded from an intramural sensor 2 mm from the electrode. Tissue 
temperature increased with power delivery and occasionally exceeded 100 degrees C at 12 
Watts (figure  ). Lesion diameter often exceeded 10 mm (figure) and plateaued after 90 to 
120 seconds of the application (figure ). Steam pops occurred at 12 Watts, but none were 
observed at 10 Watts and below, suggesting that the risk of pops can be controlled with 
limiting power delivery. 

22 
 
 
 
 
 
 
 
In-Vivo Studies with Irrigated Needle 
 
In-vivo studies were then performed in 6 goats (37 – 43 kg) and 11 swine (32 – 90 kg).7 
The LV was accessed by the retrograde aortic approach. A total of 46 needle ablation 
lesions were created. The needle was extended 5 – 7 mm. Saline solution (0.9%) was 
infused at 1 mL/min for 60 seconds and was continued during the RF application of 120 
seconds. RF power was 10 – 14 W for 9 lesions (low power group) and titrated to 30 to 40 
Watts for 37 lesions (high power group). After needle RF ablation, an endocardial surface 
lesion was created to facilitate locating the needle from endocardial inspection by applying 
RF to the dome electrode without irrigation (titrated to a 10 ohm impedance fall for 120 
seconds). The needle/endocardial lesions were compared to 18 standard RF lesions 
created with a 4 mm solid electrode with RF power titrated to a temperature of 65 degrees 
C for 120 seconds; and a second set of 17 control lesions created with a saline irrigated RF 
ablation catheter (Thermocool) with power limited to 50 Watts, temperature limited to < 
50 degrees C, flow at 30 ml/min and duration 60 to 120 seconds. 

23 
 
High power needle ablation lesions were substantially larger than standard irrigated 
lesions (figure). Low power irrigated lesions had similar depth to standard irrigated 
lesions, but depth was limited due to maximal extension of the needle and thickness of the 
ventricle. On gross examination, the lesions were typical of RF lesions, showing a region of 
central pallor and a hemorrhagic border (figure). Grossly there was no surface charring or 
thrombus. 
 
 
 

24 
 
 
 
 
Figure: Serial 1 mm sections Serial 1-mm sections through a high-power infusion-needle 
ablation lesion are shown. The sections are shown serially from the endocardium 
(“Endo”) to the epicardium (“Epi”) with depths from the endocardium marked. The 
reference bar in the first panel is 10 mm in length. The uncut (“Gross”) endocardial surface 
is seen in the final panel, and is smooth and free of char. The cross-sectional area of the 
lesion increases over the first four sections, and reaches a stable diameter which persists 
throughout the depth of the lesion. The lesion has an inner area of pallor and desiccation, 
surrounded by a narrow 
hemorrhagic rim, which is sharply demarcated from surrounding myocardium. The lesion 
tapers and ends within 1 mm of the epicardium, at a depth of 12 mm from the 
endocardium. From Sapp et al J Cardiovas Electrophys 2006;17:657 – 661.7 

25 
 
 
 
 
In-vivo Irrigated Needle with temperature monitoring from the dome and needle and 
thrombus assessment 
 
These studies limited power according to temperature at the needle or dome electrodes. 
The needle was inserted 5 – 9 mm. RF power was increased manually with temperature 
limited to 60 – 65 degrees C (dome or needle) or 55 degrees C. Irrigation was initiated at 2 
ml/min after needle extension and after 30 sec at that flow rate RF was initiated and 
continued for 90 seconds. 
 
A protocol to assess for thrombus formation at the needle was also employed. A short 
sheath was inserted into the carotid artery, though which a long sheath was inserted into 
the LV. The catheter was inserted into the LV through the long sheath After each needle 
lesion, the catheter was withdrawn into the long sheath without retracting the needle, and 
the long sheath and catheter removed and inspected for thrombus char. Animals were 
systemically anticoagulated with heparin. 
 
Control lesions (10 in 3 animals) were created with a Thermocool irrigated catheter (40 or 
50 Watts) for 60 seconds, irrigated at 30ml/min. 
 
In 5 goats 10 needle lesions were created at 60 – 65 degrees C (mean power 19.8 + 5.1 
Watts) and 11 needle lesions were created at 55 degrees C (mean power 16.8 + 4.9 Watts) 
(figure ). Lesion depth was similar to the previous studies. Lesion size was greater with 
the 60 – 65 degree C lesions. No char or thrombus was observed on the catheter or 
aspirated from the sheath after removal. 

26 
 
 
 
 
 
 
 
 
 
 
In-vivo Irrigated Needle with 50:50 contrast saline mix to assess needle position and 
perforation 
 
In 11 goats (35 – 47 Kg) ventricular lesions were created during infusion of saline contrast 
mixture. The needle was inserted 5 – 9 mm. The contrast : saline mixture was Infused for 
5 to 60 seconds then RF was applied for total infusion duration of 2 minutes with 
fluoroscopic imaging. After the last lesion, animals were sacrificed and the pericardium 
opened for inspection. Lesions were sectioned. (Zei, PC et al. Contrast-enhanced 
fluoroscopic real-time localization of intramural infusion and RF ablation with a novel 
infusion needle catheter. HRS abstract 2007) 
 
50 total needle deployments with extension of the needle outside the catheter in an 
attempt to drive it into the myocardium were performed. 
In 3 needle extensions no visible contrast seen intramurally suggesting intracavitary 
deployment. 
In 3 needle extensions pericardial staining suggesting perforation and the needle 
was withdrawn. In two, the catheter was intentionally wedged in the LV apex and the 
needle extended for intentional perforation to assess recognition of perforation. No animal 

27 
 
developed hemodynamic compromise. At Post-mortem there was a small amount of blood 
tinged pericardial fluid in all 3 of these animals 
 
 
In 44 needle deployments well defined tissue staining was observed (figure ). At post 
mortem 43 lesions identified and had a mean lesion volume 1.45+0.82 cm2. There were no 
needle dislodgements during infusion or RF application. During continued observation, 
contrast was observed to gradually dissipate with time, as is observed when tissue contrast 
staining is used to guide transeptal puncture or pericardial puncture procedures. 
 
In summary, the use of a contrast-saline mixture for initial irrigation through the needle 
allowed prompt recognition of deployment in the myocardium, penetration into the 
pericardial space, or failure to enter the myocardium. 
 
 
 

28 
 
Human Experience 
Human Experience 
The needle ablation catheter has been used with permission of the Queen Elizabeth II 
Health Sciences Center in 8 patients in Halifax Nova Scotia, Canada. Primary physician 
operators were John L. Sapp, MD and William G. Stevenson, MD. All patients had failed 
prior antiarrhythmic drug therapy and catheter ablation attempts. All had recurrent 
ventricular arrhythmias that had failed antiarrhythmic drug therapy and prior RF ablation 
attempts. For our 8 patients overall, 4 are free of ventricular tachycardia. Patients 1, 3, 5 
and 6 had recurrent arrhythmias. Patient 5 has had one episode of spontaneously 
terminating slow VT, which is a marked improvement compared to prior to ablation. There 
was one major procedure related complication, which was cardiac tamponade in patient 3. 
This patient’s course was complicated by renal failure, from which he recovered, but he 
subsequently died from heart failure (see below). In addition one patient (patient 5) had 
heart block due to ablation in the basal septum, but this was expected due to the location of 
the VT at that region.   In patient 8, ablation near the epicardial LV pacing lead rendered 
this lead no longer able to capture, as expected from RF ablation in that area. There has 
been no procedure related mortality and no embolic events. In the last three patients a 
small amount of coagulum has been noted at the hole in the dome electrode after catheter 
removal. We feel this is indicative of heating of the dome electrode as it lies on the tissue. 
The coagulum has been adherent to the dome electrode, and tiny (figures below); smaller 
than that often encountered with the use of 8 mm electrodes and occasionally even on 
irrigated electrodes, in our experience. Use of longer RF applications may be a factor in 
these patients. Details of all the 8 cases are provided below. 
 
Patient 1: 
 
13 year-old male 
Incessant VT; 70% of beats 
EF 25%; LVEDD 79 mm 
4 prior ablation procedures, including endo/epi last procedure; refractory to 
flecainide, amiodarone, beta-blockers, sotalol 
Broad area of early activation inferoapical region 
General anesthetic: suppressed ectopy 
Combination of pace mapping and activation mapping 
Suppressed with RF 
PVC2 recurred upon withdrawal of GA 
Suppressed with reintubation/sedation, limiting mapping largely to pace-mapping during 
the later part of the case. 

29 
 
Further RF delivered 
A total of 12 RF applications (3-less than 10 seconds when they had no effect on ectopy) 
No adverse effects 
 
Procedure details: 
At baseline there was ventricular bigeminy. The PVCs had RB morphology, axis -60 and 
slight variations in the notching. Activation mapping of the LV revealed early activation 
surrounding the apical inferolateral papillary muscle as visualized by ICE. The site of 
earliest activation appeared to be just distal (apical) to the papillary muscle. The earliest 
site of activation was identified, and the needle was extended. The earliest site was 10 
msec preceding the QRS on at least one PVC morphology, and had a QS morphology on the 
unipolar electrogram. RF was delivered at 3 sites that appeared promising, but PVCs 
persisted, although the initial morphology changed. Another site just distal to the initial 
sites with angulation of the tip towards the base had early activation. Extending the needle 
into the myocardium at this site revealed a site with local activation preceding the QRS by 
20 msec. RF was delivered here and abolished all ectopy. 
 
No further ectopics were seen during a further 60 minutes of testing and observation, 
including with administration of epinephrine 10 and 20 mcg, and later after esmolol to 
slow the heart rate. Rapid burst pacing failed to induce any ectopy. 
 
After the sheaths were removed and hemostasis achieved, the patient went into bigeminy 
with a different morphology PVC, more positive in V1. This had not been seen previously. 
 
Vascular access was re-obtained, this time with a Mullins sheath rather than the steerable 
Agilis sheath, and with an 8 Fr arterial sheath. 
Retrograde mapping was attempted, but electrograms appeared to have greater noise. 
Therefore we reverted to a transeptal approach and were able to re-approach the culprit 
area. Ectopics were extremely rare and so a combination of pace mapping and very limited 
activation mapping was performed. A slightly more apical portion of the same area was 
identified as the best target, and 2 needle ablation lesions were delivered. No ectopy was 
observed at all thereafter. After reversal of heparinization, sheaths were removed and the 
patient was extubated. He was transported to PICU in stable condition. There were no 
complications and only very rare ventricular ectopics observed overnight. 
 
The patient recovered from the procedure normally without evidence of complications. 
 
Holter 24 hr recording after procedure showed 3% PVCs. On day 4 after the procedure 
occasional PVCs emerged. The patient returned home to the Netherlands. By 5 weeks later 
periods of ventricular bigeminy, and occasional couplets were present. 

30 
 
 
Needle Catheter Performance 
 
When mapping was reinitiated a new catheter was inserted. With injection of saline, saline 
was observed to leak from the Redel connector of this second catheter. A third catheter 
was removed from the packaging and after the cables were plugged in it was found that the 
Hypertronics connector wasn’t securely glued into the handle as the PCB came out. A 
fourth catheter was then used without difficulty. 
 
 
 
 
 
Earliest Site: Intramyocardial 
 
 
 
Tip Bipole 
Needle Bipole 

31 
 
 
 
 
Ablation Summary 
Target Arrhythmia 
Result 
Time  
Temp 
Power 
Imp 
 
60 
Avg 
58 
14 
120 
# 1 
 
 
Max 63 
24 
185 
Comments: 
 
 
 
 
 
 
 
60 
Avg 
57 
23 
106 
# 2 
 
 
Max 61 
32 
137 
Comments: 
 
 
 
 
 
 
 
12 
Avg 
50 
19 
109 
# 3 
 
 
Max 62 
35 
122 
Comments: 
 
 
 
 
 
 
 
7 
Avg 
51 
14 
108 
# 4 
 
 
Max 60 
22 
114 
Comments: 
 
 
 
 
 
 
 
3 
Avg 
48 
9 
111 
# 5 
 
 
Max 53 
18 
113 
Comments: 
 
 
 
 
 
 
 
67 
Avg 
58 
7 
111 
# 6 
 
 
Max 60 
12 
125 
Comments: 
 
 
 
 
 
 
 
15 
Avg 
53 
14 
119 
# 7 
 
 
Max 63 
27 
130 
Comments: 
 
 
 
 
 
 
 
6 
Avg 
54 
11 
122 
# 8 
 
 
Max 62 
17 
125 

32 
 
 
Comments: 
 
 
 
 
61 
Avg 
57 
16 
94 
# 9 
Max 61 
21 
116 
Comments: 
 
 
 
 
60 
Avg 
57 
19 
95 
# 10 
Max 62 
26 
111 
Comments: 
 
 
 
 
60 
Avg 
58 
17 
92 
# 11 
Max 60 
24 
147 
Comments: 
 
 
 
 
60 
Avg 
58 
13 
92 
# 12 
Max 60 
17 
123 
 
 
Patient 2 6/15/2011 
 
This 41 year-old woman had a history of VT and cardiomyopathy diagnosed in 2006, 
attributed to prior myocarditis, based on previous MR imaging that showed subendocardial 
scar. An ICD had been placed in 2007. In early June 2011 she presented with incessant VT 
that could not be interrupted with medications. An endocardial ablation procedure was 
attempted in Winnipeg, Canada. Earliest endocardial activation was identified at the basal 
lateral LV, but irrigated RF lesions had no effect on tachycardia. Congestive heart failure 
developed and LV ejection fraction was 16%. She was transferred to Halifax for attempted 
needle catheter ablation. 
 
Intracardiac ultrasound showed a minimal pericardial effusion at baseline. The VT had axis 
-150, RBBB morphology, transition in V6 and Rs in V5.  Transeptal puncture was 
performed and the ablation catheter inserted through a large curve steerable sheath to the 
left ventricle. Activation mapping revealed earliest endocardial activation at the 
posterobasal LV where an early far-field signal was also seen. The needle was deployed 
into the myocardium at 9 sites to determine the earliest intramyocardial site. At the 10th 
site an early pre-potential was identified within the area that was earliest endocardially. A 
1 CC bolus of 50:50 contrast/hepaarinized saline was injected at this site to verify that we 
were intramyocardial. There was good contrast tissue staining, consistent with 
intramyocardial deployment. We then pre-injected at 2 mL/min heparinized saline, and 
delivered temperature-controlled RF for 60 seconds at 60 degrees, limited to 40W. The VT 
terminated within 5 seconds. RF was then restarted and continued for another 26 seconds. 
The needle was withdrawn into the catheter. Programmed ventricular stimulation with 
single and double ventricular extrastimuli were delivered, with no reinduction of VT. We 

33 
 
did not appreciate a change in the tissue and there was no change in the minimal 
pericardial effusion that had been present at baseline. 
 
The needle was reinserted to the same area and a second lesion was delivered. 
Programmed ventricular stimulation was then repeated with 1 to 3 ventricular extra- 
stimulation from two intracardiac sites at two drive cycle lengths and only brief 
polymorphic VT was inducible. 
 
There were no procedure complications and the patient recovered well. 
 
As of July 29, 2011 there was no recurrence of VT as detected by ICD. LV function had 
improved. 
 
Needle Catheter Performance 
 
There were no problems with needle catheter performance. 

34 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Ablation Summary 
Target Arrhythmia 
Result 
Time  
Temp 
Power 
Imp 
 
60 
Avg 
58 
20 
130 
# 1 
 
 
Max 62 
29 
171 
Comments: 
 
 
 
 
 
 
 
26 
Avg 
54 
11 
125 
# 2 
 
 
Max 60 
18 
150 
Comments: 
 
 
 
 
 
 
 
45 
Avg 
58 
11 
115 
# 3 
 
 
Max 60 
14 
125 

35 
 
 
Patient 3 7/27/2011 
 
68 year-old man with ischemic cardiomyopathy, heart failure, prior myocardial infarction, 
left anterior descending angioplasty, LV ejection fraction of 30%, and VT with prior ICD 
placement. Endocardial RF ablation for VT had been performed in 2008. In July 2011 he 
presented with recurrent episodes of VT, heart failure and ICD therapies despite 
amiodarone and mexiletine therapy. Another endocardial RF ablation was attempted and 
failed to control VT and he was transferred for attempted needle ablation. 
 
Procedure 
Four morphologies of VT were induced with isoproterenol and programmed stimulation 
with double extrastimuli. Initial mapping in the RV suggested that the VT was in the LV. 
Despite the use of intracardiac echocardiography transeptal puncture was performed with 
difficultly due to atrial enlargement, a large coronary sinus and posteriorly positioned fossa 
ovalis. A steerable mapping catheter was advanced to the LV through a large curve 
steerable sheath. Earliest sites for VT1 and VT2 were in the region of the left ventricular 
outflow tract immediately below the aortic valve on the septal side. Catheter stability at 
that region was difficult. We then exchanged the mapping catheter for the needle ablation 
catheter. The needle was deployed into the myocardium in this basal septal superior LV 
region. Repeated deployments were performed, as insertion into the myocardium was 
difficult with the sheath coming downward through the mitral valve and then directed the 
catheter superiorly. However, sites with intramural activation time that preceded the QRS 
onset were identified and RF ablation lesions applied. Initial lesions rendered VT1 and VT2 
no longer inducible. With isoproterenol stimulation and programmed stimulation, VT3 and 
VT 4 remained inducible, but were less reliably provokable.  Additional needle 
deployments were performed from the LV by both a transeptal and retrograde aortic 
approach. Additional deployment from the right ventricle was also performed in the basal 
septal area. A total of 48 RF applications were performed ranging from 14 to 120 seconds 
in duration. No VT was inducible with programmed stimulation during isoproterenol 
infusion. 
 
Complete heart block occurred during ablation, as anticipated from ablation in the basal 
septum in the region of the AV conduction system, but it was felt that heart block with 
control of VT would be preferable to continued VT. 
 
A small pericardial effusion was noted on intracardiac imaging during the later portion of 
the procedure, but was stable with repeated imaging. Approximately one hour later the 
patient developed hypotension and transthoracic echocardiography showed a large 
pericardial effusion, which was evacuated with a subxiphoid pericardial puncture. Over the 

36 
 
next 5 days he had acute exacerbation of (in addition to his chronic renal insufficiency) 
renal failure, which subsequently resolved. He was discharged home. Approximately 3 
months later he was readmitted to hospital for heart failure. During follow-up he had no 
further spontaneous episodes of VT, but heart failure continued to be a problem. He 
wished no further therapy, his ICD was inactivated, he was made “do not resuscitate” and 
died of heart failure. 
 
Needle Catheter Performance 
Deploying the needle into the basal LV septum was difficult, as is often the case for 
mapping this area with usual ablation catheters. From the transeptal approach it requires 
the catheter traverse the sheath into the LV, which typically points inferiorly, then flexing 
superiorly to reach the target area. It was difficult to maintain that position with sufficient 
force, such that the needle with deploy into the myocardial tissue when extruded and 
multiple attempts to insert the needle were made with failure of contrast injection to reveal 
tissue staining. After 1 hr and 35 min the irrigation solution could no longer be injected 
through the needle, indicating that it had clogged with the mixture of viscous contrast and 
saline. The catheter was replaced without incident. 
 
Complications: 
This was a challenging case due to multiple VTs from the basal septum. Heart block was an 
anticipated complication due to the location of the VT, requiring ablation in the basal 
septum, and has been observed in other VT ablation studies.(4,6). 
 
Pericardial tamponade occurs in approximately 1% of VT ablation cases (Tokuda in press). 
It is possible that it was related to myocardial puncture with the needle, or the diagnostic 
catheter in the RV during this long procedure. The transeptal puncture was also difficult 
and tamponade is a known risk. Tamponade presented over one hour after the procedure 
suggesting that the bleeding was slow and it resolved without requiring surgery. This 
course is relatively typical for tamponade related to catheter ablation. Acute renal failure 
was felt to be due to acute tubular necrosis, secondary to transient hypotension and 
hypoperfusion from cardiac tamponade on top of chronic renal failure. The patient had a 
history of heart failure and this continued after ablation. Heart failure is a major cause of 
mortality in this patient population, as has been observed in other VT ablation studies.(6) 
It is possible that the ablation procedure aggravated his heart failure, either through 
myocardial injury or disadvantaged myocardial contractility induced by pacing 
dependence, although if VT had not been controlled, this would likely have had still greater 
adverse impact. 
 
Ablation Summary 
Target Arrhythmia 
Result 
Time 
Temp 
Power 
Imp 

37 
 
 
33 
Avg 
54 
16 
108 
# 1 
Max 66 
30 
118 
Comments: 
 
 
 
 
61 
Avg 
55 
20 
97 
# 2 
Max 64 
29 
118 
Comments: 
 
 
 
 
19 
Avg 
54 
16 
99 
# 3 
Max 63 
28 
109 
Comments: 
 
 
 
 
51 
Avg 
58 
15 
93 
# 4 
Max 63 
25 
103 
Comments: 
 
 
 
 
60 
Avg 
57 
23 
94 
# 5 
Max 60 
28 
150 
Comments: 
 
 
 
 
60 
Avg 
57 
17 
95 
# 6 
Max 62 
28 
124 
Comments: 
 
 
 
 
80 
Avg 
58 
17 
99 
# 7 
Max 61 
28 
134 
Comments: 
 
 
 
 
69 
Avg 
53 
23 
90 
# 8 
Max 63 
29 
121 
Comments: 
 
 
 
 
60 
Avg 
53 
21 
100 
# 9 
Max 61 
30 
107 
Comments: 
 
 
 
 
15 
Avg 
45 
18 
108 
# 10 
Max 57 
30 
114 
Comments: 
 
 
 
 
60 
Avg 
46 
23 
110 
# 11 
Max 55 
30 
116 
Comments: 
 
 
 
 
15 
Avg 
57 
2 
134 
# 12 
Max 60 
4 
141 
Comments: 
 
 
 
 
20 
Avg 
57 
3 
130 
# 13 
Max 60 
13 
141 
Comments: 
 
 
 
 

38 
 
 
71 
Avg 
58 
5 
103 
# 14 
Max 61 
11 
128 
Comments: 
 
 
 
 
19 
Avg 
51 
14 
112 
# 15 
Max 63 
30 
123 
Comments: 
 
 
 
 
18 
Avg 
49 
20 
108 
# 16 
Max 60 
30 
113 
Comments: 
 
 
 
 
14 
Avg 
56 
3 
118 
# 17 
Max 60 
12 
124 
Comments: 
 
 
 
 
27 
Avg 
55 
16 
100 
# 18 
Max 61 
21 
119 
Comments: 
 
 
 
 
61 
Avg 
57 
21 
84 
# 19 
Max 62 
29 
97 
Comments: 
 
 
 
 
65 
Avg 
55 
26 
85 
# 20 
Max 60 
29 
103 
Comments: 
 
 
 
 
70 
Avg 
58 
16 
86 
# 21 
Max 61 
21 
106 
Comments: 
 
 
 
 
91 
Avg 
58 
15 
92 
# 22 
Max 63 
25 
133 
Comments: 
 
 
 
 
90 
Avg 
58 
13 
94 
# 23 
Max 61 
20 
133 
Comments: 
 
 
 
 
24 
Avg 
55 
15 
90 
# 24 
Max 66 
23 
108 
Comments: 
 
 
 
 
19 
Avg 
57 
8 
89 
# 25 
Max 63 
14 
91 
Comments: 
 
 
 
 
20 
Avg 
55 
8 
89 
# 26 
Max 60 
17 
93 
Comments: 
 
 
 
 

39 
 
 
61 
Avg 
58 
12 
85 
# 27 
Max 62 
19 
95 
Comments: 
 
 
 
 
61 
Avg 
58 
6 
95 
# 28 
Max 60 
12 
119 
Comments: 
 
 
 
 
91 
Avg 
57 
19 
83 
# 29 
Max 63 
30 
108 
Comments: 
 
 
 
 
30 
Avg 
42 
30 
108 
# 30 
Max 45 
37 
111 
Comments: 
 
 
 
 
28 
Avg 
43 
32 
108 
# 31 
Max 45 
35 
111 
Comments: 
 
 
 
 
36 
Avg 
42 
33 
107 
 
 
Patient 4 date: 4/17/2012 
 
The patient is a 61 year old male with previous aortic root repair, aortic valve replacement, 
inferior wall myocardial infarction, now with a left ventricular ejection fraction of 0.45. He 
had a history of recurrent ventricular tachycardia (VT) for which an ICD had been 
implanted. VT recurrences had failed to be suppressed by therapy with amiodarone and 
mexiletine and two prior endocardial catheter ablation procedures. 
 
Procedure: 
Patient was in sinus rhythm with a prolonged HV interval at the start of the case. Five 
different morphologies of monomorphic VT were inducible with programmed ventricular 
stimulation. A transeptal puncture was performed and the left ventricle accessed via the 
left atrium and across the mitral valve. Initial mapping during sinus rhythm and VT was 
performed with a Biosense Webster Surround Flow catheter and was consistent with 
inferolateral low voltage scar, but a relatively broad endocardial exit for the predominant 
VT with the endocardium not in the reentry circuit. We initially focused on VT3, which was 
felt to be the predominant clinical VT. VT3 induced and was mapped to the superior aspect 
of the inferoposterobasal scar. The initial mapping catheter was then exchanged for the 
needle catheter. Infusion needle ablation was carried out across the sites of earliest 
endocardial activation in the band between the endocardial scar margin as determined by 
bipolar electrogram (< 1.5 mV) and the apparent epicardial scar margin as determined by 

40 
 
unipolar electrogram amplitude (< 8.3 mV). Sites with close pace matches for the induced 
VTs were sought. At the site of best pace match, access to the subepicardial region was 
limited by what appeared to be a papillary muscle base and very thick tissue at this region. 
Sites with intramyocardial late potentials or where intramyocardial capture with delay 
(needle unipolar pacing) was achieved especially if a near match to an induced VT, were 
specifically targeted. During RF at a site with an early intramyocardal potential VT 
terminated, preceded by slight slowing and a PVC. The same VT recurred later additional 
RF lesions were placed in that are with the needle extended to 9 mm. 
 
Near the end of the procedure the initial VTs were not inducible with right ventricular 
outflow tract pacing. A fast poorly tolerated VT (VTE) was induced prior to the final lesions 
delivered; further testing was not performed after final lesion delivery. The patient 
recovered from the procedure well and remained free of sustained VT. There were no 
complications. He recovered well. 
 
Needle Catheter Performance: 
 
Needle applications are listed in the table from the EP lab recording system below. A total 
of 40 RF applications were delivered. As discussed above we had the impression that the 
thick myocardium over the region added to difficulty in region the reentry circuit. There 
was no difficulty in catheter maneuverability. After several applications, the resistance to 
flow through the infusion channel of the needle increased, such that it required substantial 
force to inject the saline contrast mixture, and subsequently became completely occluded. 
The catheter was exchanged. The channel of the second catheter later became partially 
obstructed, limiting infusion and probably limiting lesion creation. Both catheters were 
returned to Biosense Webster for examination. 
 
Note that in the table, the recording system resets and designates a new lesion when power 
ramps to 0 in response to reaching temperature maximum. Thus the number continuous 
applications is fewer than the total number in the table. 
 
Ablation Summary 
Target Arrhythmia 
Time  
Temp 
Power 
Imp 
 
60 
Avg 
58 
16 
113 
# 1 
 
Max 62 
27 
151 
Comments: 
 
 
 
 
 
 
61 
Avg 
58 
15 
117 
# 2 
 
Max 60 
19 
132 
Comments: 
 
 
 
 
 

41 
 
 
12 
Avg 
54 
7 
146 
# 3 
Max 62 
17 
158 
Comments: 
 
 
 
 
11 
Avg 
56 
8 
141 
# 4 
Max 63 
19 
146 
Comments: 
 
 
 
 
6 
Avg 
54 
10 
136 
# 5 
Max 63 
21 
140 
Comments: 
 
 
 
 
29 
Avg 
55 
15 
129 
# 6 
Max 63 
33 
137 
Comments: 
 
 
 
 
15 
Avg 
58 
0 
201 
# 7 
Max 60 
1 
210 
Comments: 
 
 
 
 
14 
Avg 
53 
12 
131 
# 8 
Max 62 
29 
137 
Comments: 
 
 
 
 
8 
Avg 
53 
12 
133 
# 9 
Max 62 
32 
137 
Comments: 
 
 
 
 
5 
Avg 
53 
11 
132 
# 10 
Max 59 
28 
136 
Comments: 
 
 
 
 
76 
Avg 
58 
7 
110 
# 11 
Max 60 
11 
131 
Comments: 
 
 
 
 
65 
Avg 
58 
6 
124 
# 12 
Max 61 
11 
132 
Comments: 
 
 
 
 
91 
Avg 
59 
4 
108 
# 13 
Max 60 
11 
126 
Comments: 
 
 
 
 
91 
Avg 
59 
5 
103 
# 14 
Max 60 
10 
120 
Comments: 
 
 
 
 
91 
Avg 
59 
5 
102 
# 15 
Max 61 
10 
115 
Comments: 
 
 
 
 

42 
 
 
23 
Avg 
58 
1 
132 
# 16 
Max 60 
10 
142 
Comments: 
 
 
 
 
92 
Avg 
58 
10 
111 
# 17 
Max 60 
19 
131 
Comments: 
 
 
 
 
60 
Avg 
57 
24 
88 
# 18 
Max 60 
32 
97 
Comments: 
 
 
 
 
71 
Avg 
58 
14 
96 
# 19 
Max 60 
20 
112 
Comments: 
 
 
 
 
60 
Avg 
57 
22 
93 
# 20 
Max 60 
28 
106 
Comments: 
 
 
 
 
61 
Avg 
58 
10 
101 
# 21 
Max 62 
26 
122 
Comments: 
 
 
 
 
61 
Avg 
58 
15 
92 
# 22 
Max 60 
19 
103 
Comments: 
 
 
 
 
61 
Avg 
58 
12 
97 
# 23 
Max 61 
16 
109 
Comments: 
 
 
 
 
90 
Avg 
59 
8 
94 
# 24 
Max 60 
10 
111 
Comments: 
 
 
 
 
16 
Avg 
58 
1 
120 
# 25 
Max 60 
10 
128 
Comments: 
 
 
 
 
6 
Avg 
53 
3 
122 
# 26 
Max 58 
10 
130 
Comments: 
 
 
 
 
90 
Avg 
59 
8 
101 
# 27 
Max 60 
11 
126 
Comments: 
 
 
 
 
91 
Avg 
59 
8 
95 
# 28 
Max 61 
14 
108 
Comments: 
 
 
 
 

43 
 
 
91 
Avg 
59 
8 
94 
# 29 
Max 61 
11 
110 
Comments: 
 
 
 
 
61 
Avg 
58 
11 
93 
# 30 
Max 61 
15 
107 
Comments: 
 
 
 
 
45 
Avg 
57 
9 
90 
# 31 
Max 61 
14 
94 
Comments: 
 
 
 
 
60 
Avg 
58 
10 
91 
# 32 
Max 61 
16 
105 
Comments: 
 
 
 
 
61 
Avg 
58 
8 
96 
# 33 
Max 60 
12 
109 
Comments: 
 
 
 
 
68 
Avg 
58 
5 
95 
# 34 
Max 61 
10 
113 
Comments: 
 
 
 
 
6 
Avg 
56 
1 
174 
# 35 
Max 59 
2 
178 
Comments: 
 
 
 
 
91 
Avg 
59 
4 
133 
# 36 
Max 60 
7 
179 
Comments: 
 
 
 
 
97 
Avg 
59 
4 
111 
# 37 
Max 60 
12 
146 
Comments: 
 
 
 
 
91 
Avg 
59 
3 
111 
# 38 
Max 60 
9 
135 
Comments: 
 
 
 
 
9 
Avg 
51 
10 
126 
# 39 
Max 60 
25 
134 
Comments: 
 
 
 
 
5 
Avg 
53 
11 
130 
# 40 
Max 59 
31 
143 
Comments: 
 
 
 
 
11 
Avg 
51 
12 
139 
# 41 
Max 62 
31 
162 
Comments: 
 
 
 
 

44 
 
 
26 
Avg 
58 
2 
115 
# 42 
Max 60 
11 
128 
Comments: 
 
 
 
 
54 
Avg 
58 
6 
92 
# 43 
Max 60 
9 
103 
Comments: 
 
 
 
 
90 
Avg 
59 
5 
90 
# 44 
Max 60 
8 
99 
Comments: 
 
 
 
 
84 
Avg 
34 
44 
98 
# 45 
Max 36 
50 
120 
Comments: 
 
 
 
 
80 
Avg 
33 
39 
97 
# 46 
Max 35 
50 
109 
Comments: 
 
 
 
 
119 
Avg 
33 
43 
92 
# 47 
Max 34 
45 
105 
Comments: 
 
 
 
 
60 
Avg 
59 
4 
95 
# 48 
Max 60 
9 
104 
Comments: 
 
 
 
 
60 
Avg 
62 
6 
86 
# 49 
Max 65 
9 
93 
Comments: 
 
 
 
 

45 
 
Patient 5 date: 4/18/2012 
 
The patient is a 48 year old woman with nonischemic dilated cardiomyopathy left 
ventricular ejection fraction of less than 0.40. She had recurrent ventricular tachycardia 
(VT) for which an ICD had been implanted. VT recurrences had failed to be suppressed by 
therapy with amiodarone and mexiletine and two prior endocardial catheter ablation 
procedures. The last ablation procedure in 2009 was complicated by right ventricular 
perforation requiring emergency cardiac surgery for closure of a laceration in the free wall 
of the right ventricular outflow tract that was attributed to a steam pop during ablation 
near that location. 
 
Procedure: 
Patient was in sinus rhythm with a prolonged HV interval at the start of the case. A 
transeptal puncture was performed and the left ventricle accessed via the left atrium and 
across the mitral valve. Seven different morphologies of monomorphic VT were inducible 
with programmed ventricular stimulation or catheter induced ectopy. Initial mapping 
during sinus rhythm and VT was performed with a Biosense Webster Surround Flow 
catheter. 
 
VT1 was mapped to the superior basal mitral annulus. Frequently the VT morphologies 
would change between VT1 and VT2. The needle was inserted into that area and 
midmyocardial signal preceded the QRS during VT and was earlier than the endocardial 
signal. Coronary angiography confirmed adequate distance to the left coronary system. 
Infusion needle ablation rendered this VT no longer inducible. VT2 was initiated by 
ventricular pacing and appeared to originate from the same general area near the basal 
aortic-mitral region. Further infusion needle RF lesions were delivered at site of delayed 
midmyocardial potentials, or at sites where unipolar needle pacing matched the VT 
morphology. 
 
VT4 was mapped to the inferobasal septal mitral annulus and ablated in this region. 
 
VT5 and VT6 were mapped to the septal aspect of the right ventricular outflow tract region 
and needle ablation was applied in this region both from the RV and LV sides of the sepum. 
The area of the his bundle was tagged and carefully avoided. 
 
During a relatively prolonged episode of ventricular tachycardia with borderline BP 
requiring DC cardioversion VT was mapped to the inferior basal septum and Rf was 
applied. After cardioversion heart block was observed. This site was well below the site of 
the His bundle recording. 

46 
 
Programmed stimulation for induction testing was not repeated at the end of the 
procedure, but multiple attempts at induction prior to the last RF delivery had failed to 
induce the initial VTs, inducing only the VT targeted with the last ablation. 
 
The patient recovered from the procedure well and was discharged from hospital 2 days 
after ablation. Other than AV block, there were no complications. AV block is a recognized 
complication of ablation in the region of the basal septum which was required for these 
VTs. It was surprising that it emerged following an ablation lesion that was well below the 
His bundle region, but this could have been due to expansion of a prior lesion or block of a 
portion of the left posterior fascicle in that ablation region. 
 
At 2 months interrogation of her ICD showed one slow (105/min) episode of VT that 
terminated spontaneously, which is a marked improvement compared to prior to ablation. 
 
Needle Catheter Performance: 
 
There were 21 needle RF ablation lesions delivered (table below). There was no difficulty 
in catheter maneuverability. There was no increase in resistance to flow through the 
infusion channel of the needle. 
 
Note that in the table, the recording system resets and designates a new lesion when power 
ramps to 0 in response to reaching temperature maximum. Thus the number continuous 
applications (24) is fewer than noted in the table. 
 
Target Arrhythmia 
Time  
Temp 
Power 
Imp 
60 
Avg 
57 
24 
118 
# 1 
 
Max 62 
32 
157 
Comments: 
 
 
 
 
 
60 
Avg 
58 
15 
111 
# 2 
 
Max 61 
20 
130 
Comments: 
 
 
 
 
 
61 
Avg 
58 
9 
121 
# 3 
 
Max 62 
16 
143 
Comments: 
 
 
 
 
 
60 
Avg 
57 
16 
106 
# 4 
 
Max 61 
25 
125 
Comments: 
 
 
 
 
 
61 
Avg 
58 
14 
111 
# 5 
 
Max 63 
23 
129 

47 
 
 
Comments: 
 
 
 
 
60 
Avg 
58 
8 
112 
# 6 
Max 61 
12 
133 
Comments: 
 
 
 
 
61 
Avg 
57 
20 
97 
# 7 
Max 63 
30 
119 
Comments: 
 
 
 
 
76 
Avg 
58 
13 
103 
# 8 
Max 61 
18 
120 
Comments: 
 
 
 
 
90 
Avg 
58 
13 
105 
# 9 
Max 61 
17 
124 
Comments: 
 
 
 
 
90 
Avg 
59 
8 
104 
# 10 
Max 60 
13 
117 
Comments: 
 
 
 
 
60 
Avg 
57 
22 
105 
# 11 
Max 61 
28 
191 
Comments: 
 
 
 
 
15 
Avg 
58 
2 
148 
# 12 
Max 64 
7 
154 
Comments: 
 
 
 
 
90 
Avg 
58 
16 
98 
# 13 
Max 60 
21 
136 
Comments: 
 
 
 
 
91 
Avg 
58 
16 
92 
# 14 
Max 61 
21 
110 
Comments: 
 
 
 
 
17 
Avg 
54 
12 
121 
# 15 
Max 66 
22 
129 
Comments: 
 
 
 
 
37 
Avg 
54 
22 
100 
# 16 
Max 60 
33 
123 
Comments: 
 
 
 
 
61 
Avg 
57 
20 
98 
# 17 
Max 61 
33 
120 
Comments: 
 
 
 
 
61 
Avg 
57 
14 
93 
# 18 
Max 60 
20 
105 

48 
 
 
Comments: 
 
 
 
 
61 
Avg 
57 
17 
98 
# 19 
Max 63 
31 
111 
Comments: 
 
 
 
 
90 
Avg 
58 
17 
90 
# 20 
Max 63 
28 
108 
Comments: 
 
 
 
 
5 
Avg 
56 
1 
210 
# 21 
Max 60 
3 
223 
Comments: 
 
 
 
 
5 
Avg 
58 
1 
227 
# 22 
Max 61 
3 
244 
Comments: 
 
 
 
 
93 
Avg 
58 
15 
107 
# 23 
Max 64 
29 
250 
Comments: 
 
 
 
 
41 
Avg 
57 
8 
96 
# 24 
Max 61 
13 
112 
Comments: 
 
 
 
 
 
 
 
 
Patient 6: date 6/14/2012 
 
This 63 year old man had nonischemic dilated cardiomyopathy, an ICD and recurrent VT. 
He had failed prior endocardial and epicardial attempts at catheter ablation. Access to the 
LV was obtained by a transeptal approach. The bipolar voltage map did not suggest 
endocardial scar, however, the unipolar voltage map indicated a large posterobasal region 
of low voltage, consistent with intramural or epicardial scar. The clinical VT was 
repeatedly induced with catheter manipulation, but could not be induced with 
programmed stimulation and the limited activation mapping that could be performed 
suggested that the VT exit was lateral to the aortic valve. Needle ablation lesions were 
delivered as closely as possible to the site of early activation. Needle deployment was very 
difficult here, because of difficulty achieving catheter contact. Further needle was 
delivered throughout the region of low unipolar signal amplitude from the mitral end 
toward the apical end of the low voltage area. At each site contrast was injected to verify 
intramyocardial location. Verification of loss of capture was performed after RF delivery in 
most cases. On multiple occasions very fast VT was induced with catheter manipulation or 
double extrastimuli. These failed to respond to burst pacing and required shocks on each 

49 
 
occasion. This severely limited induction testing and mapping. Induction testing was 
performed with pacing from the LV and RV. Single extrastimuli and burst pacing and 
catheter manipulation failed to induce VT at the end of the procedure. We could not be 
sure VT was abolished since it was not inducible at the beginning of the procedure. There 
were no complications and specifically no clinically evident embolic events. The patient 
recovered well but had recurrent ventricular tachycardia of a different morphology than 
observed during ablation. Amiodarone was increased. At two months of follow-up he has 
had further VT. 
 
Needle catheter performance 
 
Power was limited to 35W and temp to 60W.   Each site had 1CC 50:50 contrast/saline, 
then 2CC of saline before RF application for up to 90 sec. There were 24 RF needle 
applications. We paid attention to avoiding repeated torquing of the catheter and had no 
problems. It was difficult to deploy the needle into myocardium adjacent to the aortic valve 
from the transeptal approach as it is difficult to exert force in the cranial direction when the 
catheter must come through the mitral valve in the inferior direction. On removal of the 
catheter a tiny amount of coagulum was noted along the perimeter of the dome needle hole 
(figure 1 below left panel). 
 
 
 
 
Figure 1. Coagulum around hole in dome electrode (left) and shown after removal on 
gauze (right). 
 
 
Note that in the table, the recording system resets and designates a new lesion when power 
ramps to 0 in response to reaching temperature maximum. Thus the number continuous 
applications (24) is fewer than noted in the table. 

50 
 
 
 
Target Arrhythmia 
Time  
Temp 
Power 
Imp 
16 
Avg 
53 
19 
132 
# 1 
 
Max 65 
28 
146 
Comments: 
 
 
 
 
 
73 
Avg 
58 
20 
123 
# 2 
 
Max 62 
30 
130 
Comments: 
 
 
 
 
 
90 
Avg 
58 
16 
119 
# 3 
 
Max 63 
26 
142 
Comments: 
 
 
 
 
 
85 
Avg 
56 
23 
106 
# 4 
 
Max 63 
34 
123 
Comments: 
 
 
 
 
 
90 
Avg 
57 
25 
108 
# 5 
 
Max 61 
33 
143 
Comments: 
 
 
 
 
 
43 
Avg 
55 
20 
146 
# 6 
 
Max 60 
35 
181 
Comments: 
 
 
 
 
 
4 
Avg 
46 
12 
140 
# 7 
 
Max 59 
15 
150 
Comments: 
 
 
 
 
 
10 
Avg 
53 
16 
123 
# 8 
 
Max 62 
24 
132 
Comments: 
 
 
 
 
 
73 
Avg 
58 
22 
115 
# 9 
 
Max 63 
31 
129 
Comments: 
 
 
 
 
 
6 
Avg 
49 
11 
131 
# 10 
 
Max 60 
20 
139 
Comments: 
 
 
 
 
 
56 
Avg 
58 
18 
111 
# 11 
 
Max 63 
30 
129 
Comments: 
 
 
 
 
 
90 
Avg 
58 
20 
107 
# 12 
 
Max 64 
32 
146 
Comments: 
 
 
 
 
 
90 
Avg 
58 
22 
105 

51 
 
 
# 13 
Max 61 
32 
147 
Comments: 
 
 
 
 
90 
Avg 
58 
20 
103 
# 14 
Max 62 
29 
121 
Comments: 
 
 
 
 
90 
Avg 
58 
19 
112 
# 15 
Max 65 
33 
158 
Comments: 
 
 
 
 
7 
Avg 
54 
11 
138 
# 16 
Max 61 
18 
154 
Comments: 
 
 
 
 
79 
Avg 
57 
15 
113 
# 17 
Max 64 
32 
134 
Comments: 
 
 
 
 
17 
Avg 
54 
15 
122 
# 18 
Max 63 
25 
142 
Comments: 
 
 
 
 
71 
Avg 
58 
18 
110 
# 19 
Max 62 
30 
121 
Comments: 
 
 
 
 
90 
Avg 
58 
21 
105 
# 20 
Max 63 
34 
135 
Comments: 
 
 
 
 
90 
Avg 
58 
19 
105 
# 21 
Max 62 
34 
138 
Comments: 
 
 
 
 
36 
Avg 
57 
15 
109 
# 22 
Max 60 
21 
132 
Comments: 
 
 
 
 
90 
Avg 
58 
17 
99 
# 23 
Max 61 
24 
118 
 
 
 
*nc post = no capture at 10 ma pacing from the needle after ablation. 

52 
 
Patient 7 
 
66 year-old man with recurrent VT and nonischemic cardiomyopathy, left ventricular 
ejection fraction approximately 40%. Has an ICD, history of amiodarone pulmonary 
toxicity, and failed therapy with sotalol and mexiletine. Previous catheter ablation attempt 
performed ablation in the septum in the para-Hisian region which was acutely successful 
although caused heart block. He had biventricular ICD upgrade and unfortunately 
developed recurrent VT and ICD shocks progressing to incessant VT despite antiarrhythmic 
therapy including trials of dofetilide and flecainide. A second catheter ablation procedure 
one week ago terminated the incessant VT. Unfortunately faster VTs recurred requiring 
ICD shocks. 
 
Procedure 
 
Programmed ventricular stimulation induced sustained monomorphic VT3 that was 
moderately well tolerated hemodynamically but did not usually sustain sufficiently to allow 
extensive mapping. Pace-mapping was consistent with origin from the basal inferior LV 
septum. Infusion needle ablation lesions were delivered from the LV side. VT remained 
inducible and limited mapping in VT showed a site of early activation at the basal inferior 
LV septum. The needle was deployed and the recording from the needle was even earlier. 
RF terminated VT after which it was no longer inducible. Additional RF lesions were 
applied to that area. RV was then explored and further RF delivered with the needle 
inserted into the septum at the RV side across from the inferior basal LV from the lesion 
that terminated VT. Programmed stimulation was performed and no VT was inducible. 
During recovery occasional runs of AIVR likely arising from just inferior to the site of 
ablation were observed transiently. 
 
There were no complications and he recovered well. Following the procedure he remained 
free of recurrent VT at two months of follow-up. 
 
Needle Catheter Performance 
 
The catheter handled well. Power was limited to 35W and temp to 60W.  Each site had 
1CC 50:50 contrast/saline, then 2CC of saline before RF application for up to 90 sec. A total 
of 16 RF applications through the needle were applied. During RF application 6 
spontaneous bubbles were noted on intracardiac ultrasound, similar to those that are 
observed during standard RF ablation and that have been thought to indicate heating at 
the electrode tissue interface with increasing temperature. The catheter was removed 
and and inspected. A small ring of coagulum was noted around the dome needle hole 

53 
 
(figure 2), which was cleaned. The catheter was inspected again after lesions 12 and 
16 and no coagulum was identified. There were no thromboembolic complications. 

54 
 
 
 
 
Figure 2. Circular coagulum removed from dome electrode. 
 
 
Note that in the table, the recording system resets and designates a new lesion when power 
ramps to 0 in response to reaching temperature maximum. Thus the number continuous 
applications (24) is fewer than noted in the table. 
 
Target Arrhythmia 
Time  
Temp 
Power 
Imp 
90 
Avg 
57 
26 
77 
# 1 
 
Max 63 
33 
99 
Comments: 
 
 
 
 
 
25 
Avg 
48 
26 
84 
# 2 
 
Max 56 
33 
117 
Comments: 
 
 
 
 
 
90 
Avg 
57 
26 
69 
# 3 
 
Max 63 
34 
98 
Comments: 
 
 
 
 
 
10 
Avg 
57 
1 
163 
# 4 
 
Max 60 
3 
182 
Comments: 
 
 
 
 
 
43 
Avg 
54 
22 
81 
# 5 
 
Max 63 
34 
98 
Comments: 
 
 
 
 
 

55 
 
 
7 
Avg 
53 
9 
78 
# 6 
Max 58 
23 
85 
Comments: 
 
 
 
 
38 
Avg 
54 
15 
77 
# 7 
Max 63 
34 
85 
Comments: 
 
 
 
 
10 
Avg 
48 
18 
85 
# 8 
Max 61 
29 
93 
Comments: 
 
 
 
 
8 
Avg 
51 
12 
85 
# 9 
Max 60 
20 
88 
Comments: 
 
 
 
 
5 
Avg 
50 
12 
85 
# 10 
Max 62 
22 
90 
Comments: 
 
 
 
 
6 
Avg 
50 
17 
83 
# 11 
Max 60 
26 
88 
Comments: 
 
 
 
 
8 
Avg 
52 
13 
84 
# 12 
Max 60 
24 
88 
Comments: 
 
 
 
 
8 
Avg 
52 
15 
83 
# 13 
Max 65 
32 
88 
Comments: 
 
 
 
 
32 
Avg 
56 
21 
80 
# 14 
Max 63 
33 
86 
Comments: 
 
 
 
 
85 
Avg 
59 
10 
84 
# 15 
Max 64 
14 
102 
Comments: 
 
 
 
 
90 
Avg 
57 
26 
70 
# 16 
Max 62 
33 
127 
Comments: 
 
 
 
 
90 
Avg 
56 
15 
71 
# 17 
Max 62 
27 
85 
Comments: 
 
 
 
 
90 
Avg 
56 
27 
64 
# 18 
Max 60 
33 
105 
Comments: 
 
 
 
 

56 
 
 
13 
Avg 
53 
10 
94 
# 19 
Max 66 
28 
103 
Comments: 
 
 
 
 
72 
Avg 
53 
25 
64 
# 20 
Max 67 
33 
98 
Comments: 
 
 
 
 
90 
Avg 
58 
15 
69 
# 21 
Max 60 
22 
87 
Comments: 
 
 
 
 
36 
Avg 
47 
24 
65 
# 22 
Max 56 
33 
84 
Comments: 
 
 
 
 
10 
Avg 
52 
12 
64 
# 23 
Max 61 
24 
66 
Comments: 
 
 
 
 
17 
Avg 
53 
18 
63 
# 24 
Max 59 
33 
66 
Comments: 
 
 
 
 
24 
Avg 
54 
17 
62 
# 25 
Max 59 
30 
65 
Comments: 
 
 
 
 
90 
Avg 
57 
19 
66 
# 26 
Max 61 
33 
83 
Comments: 
 
 
 
 
90 
Avg 
58 
17 
66 
# 27 
Max 62 
28 
87 
Comments: 
 
 
 
 
56 
Avg 
55 
18 
66 
# 28 
Max 63 
32 
80 
Comments: 
 
 
 
 
9 
Avg 
53 
10 
65 
# 29 
Max 60 
23 
68 
Comments: 
 
 
 
 
5 
Avg 
51 
8 
65 
# 30 
Max 58 
17 
68 
 
 
 
 
Case 8 6/15/2012 

57 
 
 
This 70 year-old man with prior right coronary artery stent and nonischemic 
cardiomyopathy recurrent VT despite antiarrhythmic drug therapy with sotalol and 
mexiletine and had a history of amiodarone lung toxicity. Prior endocardial and then 
endocardial and epicardial RF catehter ablation ablation in May 2011 failed. Recurrent VT 
episodes continued despite therapy with sotalol and mexiletine. 
 
Procedure 
 
Programmed ventricular triple extrastimuli from the left ventricle induced two VTs: VT1 
had a cycle length of 280 ms, right bundle branch block configuration in V1 and cycle length 
of 280 ms. VT2 had a cycle length of 270 ms, right bundle branch block configuration in V1. 
A transseptal approach was taken to access the left ventricle. The endocardial bipolar 
voltage was largely normal. At the basal septum there was a reduced unipolar signal 
amplitude, as well as a small patch at the superobasal-lateral area consistent with 
intramural or epicardial scar. Frequent PVCs arose from the high basal lateral LV, and 
appeared to be epicardial (slurred QRS upstroke, and no early endocardial activation, with 
radial spread from the high basal lateral LV). Earliest endocardial activation for VT1 was at 
the high basal lateral LV. Infusion needle ablation lesions were delivered at the earliest 
area. VT1 was no longer inducible. A new VT, VT2 was induced with had a more 
superior/medial endocardial exit. Further needle RF applications into that area rendered 
this noninducible. The ICD was programmed back on at the end of the procedure. The LV 
lead was immediately above the site of best match, and indeed pacing from the LV lead had 
the best match for VT1. Aggressive needle ablation was performed immediately below the 
LV lead. As expected the LV lead no longer captured after ablation. Of note, it had been 
programmed off previously, because of concerns of possible proarrhythmia, and because 
his QRS was narrow. 
 
There were no complications. The patient recovered well and was discharged home. 
Needle Catheter Performance 
Ten needle ablation lesions were applied. On removal of the catheter a small amount of 
coagulum was noted at the needle hole in the dome (figure 3). 

58 
 
 
 
 
 
 
 
 
 
Target Arrhythmia 
Time  
Temp 
Power 
Imp 
90 
Avg 
58 
20 
133 
# 1 
 
Max 62 
31 
159 
Comments: 
 
 
 
 
 
90 
Avg 
58 
21 
122 
# 2 
 
Max 62 
29 
146 
Comments: 
 
 
 
 
 
90 
Avg 
58 
20 
130 

59 
 
 
# 3 
Max 62 
31 
159 
Comments: 
 
 
 
 
90 
Avg 
58 
20 
121 
# 4 
Max 63 
32 
147 
Comments: 
 
 
 
 
90 
Avg 
58 
16 
116 
# 5 
Max 61 
24 
142 
Comments: 
 
 
 
 
90 
Avg 
58 
21 
119 
# 6 
Max 61 
27 
140 
Comments: 
 
 
 
 
90 
Avg 
55 
18 
118 
# 7 
Max 63 
33 
132 
Comments: 
 
 
 
 
36 
Avg 
53 
26 
149 
# 8 
Max 60 
35 
171 
Comments: 
 
 
 
 
90 
Avg 
54 
26 
129 
# 9 
Max 62 
35 
191 
Comments: 
 
 
 
 
90 
Avg 
58 
18 
117 
# 10 
Max 62 
31 
137 
 
 
 
 
 
 
 
 
 
 
 
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