Pathophysiology of arrhythmias: clinical electrophysiology.

We have endeavored to relate known electrophysiologic mechanisms of arrhythmia development to clinically occurring arrhythmias, realizing that definitive conclusions can only be surmised at present. Arrhythmias that may be due to disorders of impulse formation include slow atrial, junctional, and ventricular escape rhythms, certain types of atrial tachycardias (such as those produced by digitalis), accelerated junctional (nonparoxysmal junctional tachycardia) and idioventricular rhythms, and parasystole. Arrhythmias that may be due to disorders of impulse conduction include flutter and fibrillation, atrioventricular nodal reentrant tachycardia, reciprocating tachycardias associated with an accessory pathway, sinus nodal reentry, some atrial tachycardias, and many ventricular tachycardias. Understanding the mechanism of the tachycardia, in some instances, helps direct rational therapeutic approaches.