Value of onset sequence in discriminating ventricular tachycardia from supraventricular tachycardia

A major cause of inappropriate treatment delivery by current implantable antitachycardia devices (ATDs) is failure to distinguish between paroxysmal ventricular tachycardia (VT) which requires therapy and supraventricular tachycardia (SVT) for which therapy should be suppressed. Proposed solutions to address this problem, such as morphological analysis of intracardiac electrograms, will also fail in the case of aberrantly conducted SVT. Examining the onset sequency of an arrhythmia has been proposed as an alternative for distinguishing VT from SVT. Such sequency analysis is based upon the hypothesis that VT commonly starts with one or more ventricular premature depolarizations (VPDs). Twenty-six spontaneous tachyarrhythmia onsets from 21 patients with simultaneous intraatrial and intraventricular recordings or simultaneous esophageal (atrial) and surface (ventricular) recordings were processed for interpretation of SVT and VT. The diagnosis of VT was made for onsets containing one or more VPDs; otherwise SVT was diagnosed. The algorithm diagnosed 7/7 VTs for 100% sensitivity. Specificity was 16/19 or 84%. Three cases of SVT were misdiagnosed as VT