Supraventricular tachycardia: mechanisms and treatment

Supraventricular tachycardia is a very commonly encountered cardiac arrhythmia in clinical practice. The term "supraventricular tachycardia" refers to a rapid dysrhythmia which originates at or above the level of the His bundle of the atrioventricular (AV) conduction system. Characteristically, except for tachycardia-related bundle branch block, the QRS complex during supraventricular tachycardia is identical to that seen in sinus rhythm. By using intracardiac recordings along with electrical stimulation, various mechanisms of supraventricular tachycardia have recently been delineated electrophysiologically in man. Understanding of these mechanisms provides a rational approach to the management of each specific variety of supraventricular tachycardia.