[Evaluation of the heart conduction system in patients with ventricular allorhythmia].

Intracardiac electrophysiologic studies of the sinus node and conductive system of the heart were carried out in 51 patients with ventricular allorhythmias. In half of the cases, ventricular allorhythmias occurred in patients with impaired sinus node operation and abnormal atrioventricular impulse conduction. It is suggested that anti-arrhythmic drugs associated with adverse chrono- and dromotropic effects should be used with caution.