Adenosine administration during electrophysiologic study had limited value in identifying SVT mechanisms, with no difference in AV node termination between AVRT (85%) and AVNRT (86%).
Observational (n=229)
Does the electrophysiologic response to adenosine help identify the mechanism of supraventricular tachycardia?
The electrophysiologic response to adenosine has limited diagnostic value for identifying specific SVT mechanisms, though certain features like AV block favor AT or IST.
Absolute Event Rate: 85% vs 86%
BACKGROUND: We correlated the electrophysiologic (EP) effects of adenosine with tachycardia mechanisms in patients with supraventricular tachycardias (SVT). METHODS AND RESULTS: Adenosine was administered to 229 patients with SVTs during EP study: atrioventricular (AV) reentry (AVRT; n=59), typical atrioventricular node reentry (AVNRT; n=82), atypical AVNRT (n=13), permanent junctional reciprocating tachycardia (PJRT; n=12), atrial tachycardia (AT; n=53), and inappropriate sinus tachycardia (IST; n=10). There was no difference in incidence of tachycardia termination at the AV node in AVRT (85%) versus AVNRT (86%) after adenosine, but patients with AVRT showed increases in the ventriculoatrial (VA) intervals (13%) compared with typical AVNRT (0%), P<0.005. Changes in atrial, AV, or VA intervals after adenosine did not predict the mode of termination of long R-P tachycardias. For patients with AT, there was no correlation with location of the atrial focus and adenosine response. AV block after adenosine was only observed in AT patients (27%) or IST (30%). Patients with IST showed atrial cycle length increases after adenosine (P<0.05) with little change in activation sequence. The incidence of atrial fibrillation after adenosine was higher for those with AVRT (15%) compared with typical AVNRT (0%) P<0.001, or atypical AVNRT (0%) but similar to those with AT (11%) and PJRT (17%). CONCLUSIONS: The EP response to adenosine proved of limited value to identify the location of AT or SVT mechanisms. Features favoring AT were the presence of AV block or marked shortening of atrial cycle length before tachycardia suppression. Atrial fibrillation was more common after adenosine in patients with AVRT, PJRT, or AT. Patients with IST showed increases in cycle length with little change in atrial activation sequence after adenosine.
Glatter et al. (Tue,) conducted a observational in Supraventricular Tachycardia (SVT) (n=229). Adenosine vs. Different SVT mechanisms (e.g., AVRT vs AVNRT) was evaluated on Tachycardia termination at the AV node (AVRT vs AVNRT). Adenosine administration during electrophysiologic study had limited value in identifying SVT mechanisms, with no difference in AV node termination between AVRT (85%) and AVNRT (86%).