[Criteria for a pathogenetic approach to antiarrhythmic therapy in paroxysmal supraventricular reciprocal...

An electrophysiological study using programmed transesophageal atrial pacing was performed in 106 patients with abnormalities in the myocardial conduction system, of whom 102 suffered from paroxysmal supraventricular reciprocal tachycardia and/or paroxysmal atrial fibrillation. The electrophysiological properties of the myocardial conduction system were demonstrated to be labile. The factors determining the frequency and length of palpitations were outlined. The conditions for an onset of supraventricular reciprocal tachycardiac paroxysm and for existence of a reentrant chain were found to be minimal in the effective refractory period of the accessory pathway, which was less or equal to the effective refractory period of the atrioventricular junction. An approach to antiarrhythmic therapy was proposed, which was based on modifying the ratio of the effective refractory periods of normal and abnormal excitation pathways.