A technique for the rapid diagnosis of atrial tachycardia in the electrophysiology laboratory.

OBJECTIVE The purpose of this study was to determine if the atrial response upon cessation of ventricular pacing associated with 1:1 ventriculoatrial conduction during paroxysmal supraventricular tachycardia is a useful diagnostic maneuver in the electrophysiology laboratory. BACKGROUND Despite various maneuvers, it can be difficult to differentiate atrial tachycardia from other forms of paroxysmal supraventricular tachycardia. METHODS The response upon cessation of ventricular pacing associated with 1:1 ventriculoatrial conduction was studied during four types of tachycardia: 1) atrioventricular nodal reentry (n = 102), 2) orthodromic reciprocating tachycardia (n = 43), 3) atrial tachycardia (n = 19) and 4) atrial tachycardia simulated by demand atrial pacing in patients with inducible atrioventricular nodal reentry or orthodromic reciprocating tachycardia (n = 32). The electrogram sequence upon cessation of ventricular pacing was, categorized as "atrial-ventricular" (A-V) or "atrial-atrial-ventricular" (A-A-V). RESULTS The A-V response was observed in all cases of atrioventricular nodal reentrant and orthodromic reciprocating tachycardia. In contrast, the A-A-V response was observed in all cases of atrial tachycardia and simulated atrial tachycardia, even in the presence of dual atrioventricular nodal pathways or a concealed accessory atrioventricular pathway. CONCLUSIONS In conclusion, an A-A-V response upon cessation of ventricular pacing associated with 1:1 ventriculoatrial conduction is highly sensitive and specific for the identification of atrial tachycardia in the electrophysiology laboratory.