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 respons e upon cessation of ventricular pacing associated with 1:1 ventriculoatrial conduction during paroxysmal supraventricular tachycardia is a useful diag nostic maneuver in the electrophysiology laboratory. BACKGROUND. Despite Various maneuvers, it can be difficult to differentiate atrial tachycardia from other forms of paroxysmal supraventricular tachyca rdia. METHODS. The response upon cessation of ventricular pacing associated with 1:1 ventriculoatrial conduction was studied during four types of tachycardi a: 1) atrioventricular nodal reentry (n = 102), 2) orthodromic reciprocatin g tachycardia (n = 43), 3) atrial tachycardia (n = 19) and 4) atrial tachyc ardia simulated by demand atrial pacing in patients with inducible atrioven tricular nodal reentry or orthodromic reciprocating tachycardia (n = 32). T he electrogram sequence- upon cessation of ventricular pacing was, categori zed as "atrialventricular" (A-V) or "atrial-atrial-ventricular" (A-A-V). RESULTS. The A-V response was observed in all cases of atrioventricular nod al 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 pat hways or a concealed accessory atrioventricular pathway. CONCLUSION. 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 electrophy siology laboratory. (C) 1999 by the American College of Cardiology.