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In this condition, the normal heartbeat passing from the hearts upper to lower chambers is interrupted. This result in a condition called a “heart block.” When a heart block occurs the heart rate usually slows considerably. This can result in inadequate blood flow to the brain and fainting.Take a look at this animation of your heart's electrical system for a better understanding of what happens normally:
Take a look at this animation of your heart's electrical system for a better understanding :
Heart rate and rhythm are usually analyzed with an EKG (ECG or ElectroCardioGram).
- 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 prolonged.
- 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 EKG during an attack.
- Attacks can happen a number of times in one day.
Typically, complete (third-degree) heart block is seen on the ECG during an attack.
- The condition is usually associated with Coronary artery 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.
- There may be a familial tendency to Stokes-Adams attacks. This was first recognised by William Osler in 1903, within his own family.
- History of other episodes.
- Past medical history, including history of heart disease.
- Drug history: could medication be contributing?
- Blood pressure examination (supine and standing).
- EKG: this may be normal by the time the patient is seen or may show heart block.
- If underlying heart disease is suspected, this should be investigated appropriately.
- If seizure activity has been witnessed, the possibility of epilepsy should be investigated.
Other conditions should be be considered or excluded in a patient suspected of Adams-Stokes:
- Epilepsy (if convulsions occur).
- Vasovagal fainting.
- Carotid sinus hypersensitivity.
- Orthostatic hypotension.
- A fast arrhythmia (may also reduce cardiac output but does not usually have the same brief but dramatic effect).
- Drop attacks.
- Transient ischemic attack (TIA or mini stroke).
- Syncope due to hypovolemia.
- Reversible causes such as drug toxicity should be addressed.
- Underlying heart disease should be managed appropriately.
- A cardiac pacemaker may be required.
Ask Doctor T. Blog
My 12 yr old son (140cm, 38kg) had a recent episode last month of sudden fainting, hit the back of his head on the concrete at high speed. Was unconscious for under a minute. Went to emergency via ambulance and his ECG showed QT prolonged 492ms. Question 1.Could the knock on his head of caused this ? (he did have a previous episode of unconsciousness but it was...