Diagnostic utility of early premature ventricular complexes in differentiating atrioventricular reentrant and atrioventricular nodal reentrant tachycardias

His-refractory premature ventricular complexes perturbing a supraventricular tachycardia (SVT) establish the presence of an accessory pathway (AP). Earlier premature ventricular complexes (ErPVCs) may perturb SVTs but are considered nondiagnostic.The purpose of this study was to test the hypothesis that an ErPVC will always show a difference35 ms in its advancement of the next atrial activation during atrioventricular nodal reentrant tachycardia (AVNRT). During atrioventricular reentrant tachycardia (AVRT), a PVC delivered close to the circuit can result in greater advancement of atrial activation due to retrograde conduction via an AP. Thus, an AP response, defined as ErPVC (HSixty-five consecutive patients with SVT were retrospectively evaluated. ErPVCs were defined when the ventricular pacing stimulus was35 ms ahead of the His during tachycardia.Among the 65 cases, 43 were AVNRT and 22 AVRT. Fourteen AVRT cases had an AP response with a mean HAn AP response to PVCs (A