Adams-Stokes syndrome overview

# Overview
Adams-Stokes syndrome is a sudden collapse into unconsciousness due to a disorder of heart rhythm causing heart blocks in which there is a slow or absent pulse resulting in decreased blood flow to the brain causing syncope (fainting) with or without convulsions. High grade arrhythmias often lead to abrupt decrease in cardiac output and transient loss of consciousness.

# Historical Perspective
- It is named after two Irish physicians, Robert Adams (17911875) and William Stokes (18041877).
- It was first described by Marcus Gerbezius and referenced by Morgagni later in 1761 with his two cases.

# Classification
- There is no established system for the classification of Adam Stokes Syndrome.

# Pathophysiology
- The attacks are caused by loss of cardiac output due to cardiac asystole, heart block, or ventricular fibrillation. The resulting lack of blood flow to the brain is responsible for the syncope.

# Causes
- Causes of Adams-Stokes syndrome include asystole, heart block, or ventricular fibrillation.
- Paroxysmal supraventricular tachycardia or atrial fibrillation has been reported as the underlying cause in up to 5% of patients in one series.

# Differentiating Any Disease from other Diseases
Adam Stokes Syndrome should be differentiated from other causes of syncope. These include:
- Vasovagal Fainting
- Orthostatic hypotension
- Carotid Sinus Hypersensitivity
- Syncope due to hypo-perfusion
- Epilepsy 

# Risk Factors
- The risk factors evident with Adam Stokes Syndrome includes :
- Acute Rheumatic Fever especially in pediatric patients.
- Supraventricular dysrhythmias 

# Screening
- There is insufficient evidence to recommend routine screening for Adam Stokes Syndrome.

# Epidemiology and Demographics
- The syndrome was first described and published in 1717 by Marco Gerbec.
- There may be a associated family history with Adam-Stokes attacks. This was first recognised by William Osler in 1903 within his own family.

# Natural History, Complications and Prognosis
- If undiagnosed (or untreated), Stokes-Adams attacks have a 50% mortality within a year of the first episode.
- The prognosis following treatment is very good.
- However, if attacks occur after a myocardial infarction, the prognosis is bad.

# Diagnosis

## History and Symptoms
- Stokes-Adams attacks may be diagnosed from the history, with paleness prior to the attack and flushing after recovery is particularly characteristic.
- Loss of consciousness.
- If the attack is prolonged, it may lead to seizure-like-activity.

## Physical Examination
- Prior to an attack, the patient may become pale, their heart rhythm experiences a temporary pause, and collapse may follow.
- Normal periods of unconsciousness last approximately thirty seconds; if seizures are present, they will consist of twitching after 1520 seconds.
- Breathing continues normally throughout the attack, and so on recovery the patient becomes flushed as the heart rapidly pumps the oxygenated blood from the pulmonary beds into a systemic circulation which has become dilated due to hypoxia.
- As with any syncopal episode that results from a cardiac dysrhythmia, the faints do not depend on the patient's position.
- If they occur during sleep, the presenting symptom may simply be feeling hot and flushed on waking.

## Electrocradiogram
- The ECG will show asystole or ventricular fibrillation during the attacks.
- Typically, complete or third heart block is seen on the ECG during an attack but other ECG abnormalities such as tachy-brady syndrome have also been reported.
- Torsades de pointes can also been seen.

# Echocardiography or Ultrasound
- Echocardiography may be helpful in the diagnosis of underlying heart disease.

# CT scan
- There are no CT scan findings associated with placental aromatase deficiency.

# MRI
- There are no MRI findings associated with placental aromatase deficiency.

# Other Imaging Findings
- There are no other imaging findings associated with placental aromatase deficiency.

# Other Diagnostic Studies
- There are no other diagnostic studies associated with placental aromatase deficiency.

# Treatment

## Medical Therapy
- Initial treatment can be medical, involving the use of drugs like isoproterenol (Isuprel)and epinephrine (Adrenaline).
- Most patients who develop tachycardia or bradycardia syndromes are managed with supplementary anti-arrhythmic treatment.
- Long-term anticoagulation is required in some patients. 

## Surgery
- Definitive treatment is surgical, involving the insertion of a pacemaker  most likely one with sequential pacing such as a DDI mode as opposed to the older VVI mechanisms.