Junctional rhythm - A suitable surrogate endpoint in catheter ablation of atrioventricular nodal reentry tachycardia?

Introduction: Current AHA/ACC guidelines state that junctional rhythm (JR) is an acceptable endpoint in patients undergoing radiofrequency ablation (RFA)for narrow complex tachycardia in the presence of dual AV nodal physiology, but in the absence of inducible AVNRT. Only limited data are available on the utility of JR as a marker of successful slow path way ablation. We sought tofurther characterize the sensitivity, specificity, and predictive value of JR in AVNRT oblation. Methods: A retrospective analysis was performed of 387 consecutive patients with documented narrow complex tachycardia referred for ablation, with dual AV nodal physiology and inducible AVNRT at electrophysiological study. RFA of slow pathway was performed, with the presence or absence of JR recorded for each application and inducibility tested using atrial stimulation protocol and isoproterenol. Results: Successful ablation was achieved in 385 of 387 patients using a total of 1,861 applications of radiofrequency energy. JR occurred in 692 applications, giving a sensitivity and specificity of JR as an indicator of successful ablation of 99.5% and 79.1% and a positive predictive value of 55.5%. Conclusions: This study confirms that successful oblation of slow path way seldom occurs in the absence of JR. Although JR almost invariably occurs with successful ablation, its lack of specificity and low positive predictive value questions the use of it as an endpoint in AVNRT ablations, and the guidelines should reflect this