Higher ablation temperatures (63°C vs 54-57°C) during slow pathway ablation for AVNRT correlated with abrupt termination of accelerated junctional rhythm and abolition of all SP activity (P=0.0002).
Observational (n=50)
Does the pattern of accelerated junctional rhythm during slow pathway ablation correlate with ablation temperature and residual slow pathway activity in patients with AVNRT?
Higher ablation temperatures during slow pathway ablation for AVNRT are associated with an abruptly ending pattern of accelerated junctional rhythm and the complete abolition of slow pathway activity.
p-value: p=0.0002
INTRODUCTION: Although accelerated junctional rhythm (AJR) is a known marker for successful slow pathway (SP) ablation sites, AJR may just be a regional effect of the anisotropic conduction properties of this area of the heart. We believe that detailed assessment of the AJR might provide insight into the SP specificity of this AJR and perhaps the nature of the SP itself. METHODS AND RESULTS: Our ablation protocol consisted of 30-second, 70 degrees C temperature-controlled ablation pulses with assessment after each pulse. Serial booster ablations were performed at the original successful site and at least 2 to 3 nearby sites to assess for residual AJR after the procedure in 50 consecutive SP ablations. We defined three distinct patterns of AJR: continuous AJR that persisted until the end of energy delivery (group I, 25 patients); alternating or "stuttering" AJR that persisted throughout energy delivery (group II, 9 patients); and AJR that ended abruptly during energy delivery (group III, 16 patients). Mean ablation temperatures in the three groups was 57 degrees+/-5 degrees C, 54 degrees+/-5 degrees C, and 63 degrees+/-5 degrees C, respectively (P = 0.0002 for groups I and II vs group III). Ten of 34 (29%) patients in groups I and II ("low-temperature ablation") exhibited residual SP (jump and/or single echo beats) despite tachycardia noninducibility, and 25 of 34 (73%) patients had residual AJR during the booster ablations, but neither of these was seen in any group III patients. CONCLUSION: Ablation temperature correlates with the pattern of AJR produced during SP ablation. That higher temperature lesions simultaneously abolish all SP activity as well as the focus of AJR suggests that this AJR is specific for the SP and is not a nonspecific regional effect.
Wagshal et al. (Wed,) conducted a observational in Atrioventricular Nodal Reentrant Tachycardia (n=50). Slow pathway catheter ablation was evaluated on Mean ablation temperatures across three distinct patterns of accelerated junctional rhythm (p=0.0002). Higher ablation temperatures (63°C vs 54-57°C) during slow pathway ablation for AVNRT correlated with abrupt termination of accelerated junctional rhythm and abolition of all SP activity (P=0.0002).