An abnormally fast but regular heart-rate that occurs in episodes lasting for several hours or days. Supraventricular tachycardia occurs when abnormal electrical impulses that arise in the atria of the heart take control of the heartbeat from the sinoatrial node. Symptoms include palpitations, breathlessness, chest pain, or fainting (see Stokes–Adams syndrome). Diagnosis is by an ECG. An attack can sometimes be terminated by Valsalva’s manoeuvre or by drinking cold water. Recurrent attacks are treated with antiarrhythmic drugs. Rarely, the condition may require application of an electric shock to the heart (see defibrillation).
Supraventricular tachycardia |
|
|