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Persistence of Single Echo Beat Inducibility After Selective Ablation of the Slow Pathway in Patients with Atrioventricular Nodal Reentrant Tachycardia:
Author(s) -
TONDO CLAUDIO,
BELLA PAOLO DELLA,
CARBUCICCHIO CORRADO,
RIVA STEFANTA
Publication year - 1996
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1111/j.1540-8167.1996.tb00576.x
Subject(s) - medicine , ablation , cardiology , effective refractory period , tachycardia , refractory period , nodal , beat (acoustics) , catheter ablation , reentry , radiofrequency ablation , atrioventricular reentrant tachycardia , accessory pathway , physics , acoustics
Residual Slow Pathway Conduction Effects on AVN Function. Introduction : Residual slow pathway conduction with or without reentrant echo beats has been reported in 25% to 30% of patients undergoing ablation for AV nodal reentrant tachycardia (AVNRT). Methods and Results : Fifty‐eight consecutive patients (aged 45 ± 12 years) with slow‐fast AVNRT underwent radiofrequency catheter ablation of the slow AV nodal pathway (SP). Residual slow‐fast echo beat was documented in 21 (36%) of 58 patients (group A). The pre‐and postablation AH intervals triggering the echo beats were similar (346 ± 8 msec vs 352 ± 6 msec, P = NS), as were the pre‐and postablation echo zones (55 ± 6 msec vs 52 ± 5 msec, P = NS) and functional refractory period of the SP. A consistent prolongation of the AV nodal effective refractory period (AVN‐ERP; from 265 ± 28 msec to 340 ± 50 msec, P < 0.001) and the Wenckebach cycle length (WBCL; from 298 ± 41 msec to 438 ± 43 msec, P < 0.001) was observed in all patients with abolition of SP conduction (group B). In group A patients, the prolongation of WBCL was less (285 ± 33 msec preablation, and 334 ± 41 msec postablation, P < 0.001). Additional pulses abolished the residual echo in 16 of 21 patients, and further prolongation of the AVN‐ERP and WBCL comparable to those found in patients without a residual echo beat was observed. During 19 ± 8 months follow‐up, no patient had clinical recurrence of AVNRT. Conclusion : Residual single echo beat after SP ablation for AVNRT reflects the persistence of some portion of the SP with unchanged functional conduction properties whose prognostic significance is uncertain. A consistent increase of WBCL can be a reliable marker of complete abolition of slow pathway conduction and termination of AVNRT.