[Concept of the polyfascicular structure of the atrioventricular junction in patients with reciprocal paroxysmal nodal tachycardias].

Intracardiac electrophysiologic studies were carried out in 41 patients with paroxysmal supraventricular tachycardias. Reciprocal atrioventricular tachycardia due to dissociated conduction through the atrioventricular junction was diagnosed in 29 patients. Electrophysiologic data suggested trifascicular atrioventricular conduction in 4 patients, and quadrifascicular conduction in 2. A concept of polyfascicular impulse conduction through the atrioventricular junction in some cases of reciprocal nodal tachycardia is proposed. It is demonstrated that combinations of congenital cardiac conduction abnormalities may be possible in the same individual.