Intermittent ventricular pacing during supraventricular tachycardia-Tachycardia within a tachycardia?

Supraventricular tachycardias (SVT) are not uncommon phenomena in patients implanted with permanent pacemakers for sinus node dysfunction, especially in the presence of intact atrioventricular conduction. The utility of bedside programming maneuvers and intracardiac electrograms from device interrogation, coupled with observation from telemetry during the tachycardia, makes a clinical diagnosis of the underlying arrhythmia possible even before a definitive electrophysiological study in the EP laboratory. The present case elucidates the usefulness of combining the triumvirate of non-invasive strategies to arrive at a clinical diagnosis and aid in the management of the SVT.