Stokes-Adams attacks

Synonyms: Adams-Stokes, Morgagni, Morgagni-Adams-Stokes and Spens' syndrome

What is a Stokes-Adams attack?

A classic Stokes-Adams attack is a collapse without warning, associated with loss of consciousness for a few seconds¹ . Typically, complete (third-degree) heart block is seen on the ECG during an attack (but other ECG abnormalities such as tachy-brady syndrome have been reported)¹ .

Cardiologists and other doctors specialising in syncope do not use the term 'Stokes-Adams attack' as often these days. The development of investigation techniques and improvements in the understanding of the physiology of the cardiovascular system have meant that there has been a move away from clinical diagnoses to a more rigid diagnostic classification¹ .

Epidemiology

• The condition is usually associated with coronary heart disease and so tends to occur in the elderly.

• Stokes-Adams attacks have been reported in much younger age groups, including those with congenital heart block^{2 3} .

• There may be a familial tendency to Stokes-Adams attacks. This was first recognised by William Osler in 1903 within his own family⁴ .

Stokes-Adams attack causes

With congenital heart block, it has been described as being precipitated by bradycardia or tachycardia.

• Heart block may result from:
  

  • Myocardial infarction.

  • Fibrosis (usually associated with ischaemia).

  • Atrioventricular (AV) nodal disease.

  • Structural or valvular heart disease.

  • Myocarditis.

  • Electrolyte disturbance.

  • Drugs.

  • Rheumatic diseases including ankylosing spondylitis, reactive arthritis, rheumatoid arthritis, scleroderma.

  • Infiltrative processes including amyloidosis, sarcoidosis, cardiac tumours, Hodgkin's disease, multiple myeloma.

• Stokes-Adams attacks have been described as due to:
  

  • Chronic or paroxysmal AV block.

  • Sino-atrial (SA) block.

  • Paroxysmal supraventricular tachycardia or atrial fibrillation.

Stokes-Adams attack symptoms

• There is collapse, usually without warning.

• Loss of consciousness is usually between about 10 and 30 seconds.

• Pallor, followed by flushing on recovery, can be reported.

• Some seizure-like activity sometimes occurs if the attack is prolonged¹ .

• If anyone manages to check the pulse during an episode, it will be slow, usually less than 40 beats per minute.

• Recovery is fairly rapid, although the patient may be confused for a while afterwards.

• Typically, complete (third-degree) heart block is seen on the ECG during an attack but other ECG abnormalities such as tachy-brady syndrome have been reported¹ . (The separate article ECG Identification of Conduction Disorders describes a complete heart block in more detail.)

• Attacks can happen a number of times in one day.

• They are not posture-related.

Assessment

See the separate Syncope article, which details the assessment of a patient with a syncopal episode. Briefly, this should include:

• History of other episodes.

• Past medical history, including history of heart disease.

• Drug history: establish whether medication might be contributing.

• Blood pressure examination (supine and standing).

• Cardiovascular examination.

• 12-lead ECG: this may be normal by the time the patient is seen or may show heart block or ischaemic changes; 24-hour ECG may show changes during attacks.

• Routine haematological and biochemical investigations.

• If underlying heart disease is suspected, this should be investigated appropriately.

• If seizure activity has been witnessed, the possibility of epilepsy should be investigated.

Differential diagnosis

This is the differential diagnosis of syncope and includes the following:

• Epilepsy (if convulsions occur).

• Vasovagal fainting.

• Carotid sinus hypersensitivity.

• Orthostatic hypotension.

• A fast tachyarrhythmia (may also reduce cardiac output but does not usually have the same brief but dramatic effect).

• Drop attacks.

• Transient ischaemic attack.

• Syncope due to hypoperfusion - eg, due to hypovolaemia.

Stokes-Adams attack treatment

• Reversible causes such as drug toxicity should be addressed.

• Underlying heart disease should be managed appropriately.

• A cardiac pacemaker may be required⁵ .

Driving and other activities

• If a person is susceptible to syncope with little or no warning then driving must be forbidden, at least until a diagnosis is made and a pacemaker is working well⁶ .

• Other behaviours in which sudden loss of consciousness may pose a risk also need to be addressed. These may include cycling, swimming and operating machinery.

Historical background

• William Stokes (1804-1877) and Robert Adams (1791-1875) were both Irish physicians.

• Adams' description of syncope associated with bradycardia dates back to 1827 and Stokes described the same association in 1846. (Stokes is also remembered for Cheyne-Stokes breathing.)

• Thomas Spens (1764-1842), a Scottish physician, also described a similar syndrome.