Diagnostic value of tachycardia features and pacing maneuvers during paroxysmal supraventricular tachycardia

OBJECTIVES The purpose of this prospective study was to quantitate the diag nostic value of several tachycardia features and pacing maneuvers in patien ts with paroxysmal supraventricular tachycardia (PSVT) in the electrophysio logy laboratory. BACKGROUND No study has prospectively compared the value of multiple diagno stic tools in a large group of patients with PSVT. METHODS One hundred ninety-six consecutive patients who had 200 inducible s ustained PSVTs during an electrophysiology procedure were included. The dia gnostic values of four baseline electrophysiologic parameters, nine tachyca rdia features and five diagnostic pacing maneuvers were quantified. RESULTS The only tachycardia characteristic that was diagnostic of atrioven tricular (AV) nodal reentry was a septal ventriculoatrial (VA) time of <70 ms, and no pacing maneuver was diagnostic for AV nodal reentry. An increase in the VA interval with the development of a bundle branch block was the o nly tachycardia characteristic that was diagnostic for orthodromic tachycar dia, but it occurred in only 7% of all tachycardias. An atrial-atrial-ventr icular response upon cessation of ventricular overdrive pacing was diagnost ic of atrial tachycardia, and this maneuver could be applied to 78% of all tachycardias. Burst ventricular Facing excluded atrial tachycardia when the tachycardia terminated without depolarization of the atrium, but the resul t could be obtained only in 27% of patients. CONCLUSIONS This prospective study quantitates the diagnostic value of mult iple observations and pacing maneuvers that are commonly used during PSVT i n the electrophysiology laboratory. The findings demonstrate that diagnosti c techniques rarely provide a diagnosis when used individually. Therefore, careful observations and multiple pacing maneuvers are often required for a n accurate diagnosis during PSVT. The results of this study provide a usefu l reference with which new diagnostic techniques can be compared. (C) 2000 by the American College of Cardiology.