Re-evaluation of ventrioatrial conduction

Objective To re_evaluate electrophysiological characteristics of atrioventricular and ventrioatrial conduction and to elucidate mechanism of lack or significant decrease of ventrioatrial conduction compared with atrioventricular conduction. Methods One hundred twenty eight patients,underwent cardiac intervention,atrial and ventricular stimulations were performed to observe electrophysilogical characteristics of atrioventricular and ventrioatrial conduction during interventional procedures. Results Atrioventricular conduction Wenckeback point was below 150 beat per minute in 107 of 128 patients.Twelve patients(11.2%) had ventrioatrial conduction,but Wenckeback point was below 130 beat per minute except 2 patients with Wenckeback point of 130 beat per minute.Other 95 patients(88.8%)and 21 patients with complete atrioventicular conduction block had no ventrioatrial conduction. Conclusion Intrinsic atrioventricular conduction ability is poor,representing unidirectional conduction in majority of cases. Atioventricular accessory pathway and /or fast pathway of atrioventricular node are major causes of good ventrioatrial conduction and also essential mechanism of paroxysmal superventricular tachycardia.