Pacing maneuver in the diagnosis of the mechanism of supraventricular tachycardia.

Pacing and entrainment maneuvers are essential for establishing the mechanism of supraventricular tachycardia (SVT), but may fail to do so if the SVT terminates or if pacing results in atrioventricular (AV) dissociation as opposed to entrainment of the arrhythmia. We present an unusual case of typical AV nodal reentrant tachycardia (AVNRT) with high degree AV block in which the diagnosis was confirmed using a novel maneuver consisting of simultaneous atrial and ventricular (A + V) pacing. The reproducible response to A + V pacing at varying cycle lengths established the diagnosis of AVNRT in this case.