The electrophysiologic properties in children at long term follow up after radiofrequency catheter ablation of the slow pathway due to atrioventricular nodal reentrant tachycardia (original) (raw)
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Medicina (Kaunas, Lithuania), 2009
Radiofrequency ablation of the slow pathway is an effective method of treatment in children with atrioventricular nodal reentrant tachycardia. The aim of our study was to evaluate anterograde conduction properties in children before and after radiofrequency ablation of the slow pathway and to determine the efficacy and safety of this method. Noninvasive transesophageal electrophysiological examination was performed in 30 patients at the follow-up period (mean duration, 3.24 years) after radiofrequency ablation of the slow pathway. The slow pathway function was observed in 13 patients one day after ablation, in 26 patients during the follow-up period, and in 28 patients after administration of atropine sulfate. Atrioventricular node conduction was significantly decreased the following day after ablation and at the follow-up versus the preablation (165.2 [30.2] bmp and 146.3 [28.5] bpm versus 190.9 [31.4] bpm; P<0.001). The atrioventricular node effective refractory period prolonge...
American Heart Journal, 1997
Twenty-two patients (group 1 ) with AV node reentrant tachycardia and a baseline fast pathway effective refractory period (ERP) >500 msec were compared with 30 consecutive patients (group 2) with AV node reentrant tachycardia and a fast pathway ERP <500 msec. Both groups underwent slow pathway ablation. In the patients with complete elimination of slow pathway, the fast pathway ERP and shortest 1 : 1 conduction cycle length shortened significantly after ablation but was greater in group 1 (n = 14) than in group 2 (n = 21) (125 + 78 msec vs 48 + 29 msec, p < 0.001 and 103 + 72 msec vs 52 _+ 30 msec, p < 0.001, respectively). In group 1, the shortening of fast pathway ERP was correlated to baseline difference between anterograde fast and anterograde slow ERP (r = 0.806, p < 0.001, slope = 1.08), and the shortening of fast pathway shortest 1:1 conduction cycle length was correlated to baseline difference between anterograde fast and anterograde slow shortest 1:1 conduction cycle length (r = 0.885, p < 0.001, slope = 1.47). During follow-up bradycardia did not develop in any patient and no one required pacing. This shortening of the fast pathway ERP and shortest 1:1 conduction cycle length after complete elimination of slow pathway reduced the concern of subsequent impairment of AV node conduction. (Am HeartJ 1997;134:387-94.) The mechanism of atrioventricular (AV) node reentry is based on a substrate with two functionally or anatomically distinct AV node pathways that permit reciprocation. The fast pathway has a shorter conduction time and a longer effective refractory period (ERP), whereas the slow pathway has a longer conduction time and a shorter ERP. 1-3 Radiofrequency catheter ablation techniques could provide a permanent cure and offer an option for control of symptoms in these patients. 4-6
Journal of Cardiovascular Electrophysiology, 1997
Methods and Results: Forty consecutive patients wbo underwent successful ablation of the slow pathway were prospective subjects for tbe study. Isoproterenol was used to enhance conduction and to differentiate interactive mechanisms. Potential electrotonic interactions were assessed by comparing patients with and tbose without residual dual AV node pbysiology after slow patbway ablation. Paired and unpaired f tests were used wben appropriate. P < 0.05 was considered statistically significant. In the entire study population, heart rates were not significantly different before and after slow pathway ablation (RR = 770 ± 114 msec before and 745 ± 99 msec after, P = 0.07). Anterograde fast pathway conduction properties were unchanged after slow pathway ablation (effective refractor> period, 348 ± 84 msec before and 336 ± 86 msec after, P = 0.13; shortest 1:1 conduction, 410 ± 93 msec before and 4(>0 ± 82 msec after, P = 0.39). Retrograde fast patbway cbaracteristics also were similar before and after ablation. Neither anterograde nor retrograde last patbway conduction properties during i.soproterenol infusion were changed by slow pathway ablation. When tbe study population was further divided into patients with (n = 13) or without (n = 27) residual dual AV node pbysiology, no significant change was detected in fast pathway function in either group after slow patbway ablation.
Europace, 2006
Aim The occurrence of accelerated junctional rhythm during radiofrequency energy delivery at the region of the slow pathway is a well-recognized marker of successful treatment of atrioventricular nodal re-entry tachycardia (AVNRT). Our aim was to evaluate if the quantity and duration of accelerated junctional rhythm during radiofrequency ablation of the slow pathway is correlated with residual slow pathway conduction. Methods and results Forty consecutive patients with AVNRT undergoing radiofrequency ablation of slow pathway who developed accelerated junctional rhythm during ablation were included. We compared accelerated junctional rhythm quantity and duration between two groups: group A, without echo beats and group B, with echo beats on post-ablation electrophysiology study. The total amount of accelerated junctional rhythm was significantly greater in group A than in group B [75.0 (63.5-165.0) vs. 36.0 (24.0-65.0), P ¼ 0.006], as well as total duration of accelerated junctional rhythm [47.0(33.5-81.0) s vs. 23.0 (16.0-42.0) s, P ¼ 0.006]. The cycle length of accelerated junctional rhythm did not differ between the two groups [510.0 (445.0-545.0) ms vs. 500.0 (450.0-585.0) ms, P ¼ 0.5). Conclusions The amount and duration of accelerated junctional rhythm is correlated with the total abolishment abolition of slow pathway conduction. A higher amount and duration of accelerated junctional rhythm during radiofrequency applications may be an additional marker of successful ablation.
Journal of Cardiovascular Electrophysiology, 1993
AV Nodal Behavior After Ablation. Introduction; The objective of this report is to delineate the atrioventricular (AV) nodal electrophysiologic behavior in patients undergoing fast or slow pathway ablation for control of their AV nodal reentrant tachycardia (AVNRT).Methods and Results: One hundred sixteen consecutive patients with symptomatic AVNRT were included. Twenty-two patients underwent fast pathway ablation with complete abolition of AVNRT in all and development of complete AV block in five patients. Of 17 patients with intact AV conduction postablation, 12 had demonstrated antegrade dual pathway physiology during baseline study, which was maintained in three and lost in nine patients postablation. Two patients with successful fast pathway ablation developed uncommon AVNRT necessitating a slow pathway ablation. Twenty-one patients demonstrated both common and uncommon forms of AV nodal reentry during baseline study. The earliest site of atrial activation was close to the His-bundle recording site (anterior interatrial septum) during common variety and the coronary sinus ostium (posterior interatrial septum) during the uncommon AV nodal reentry in all 21 patients. Ninety-six patients underwent successful slow pathway ablation. Among these, the antegrade dual pathway physiology demonstrable during baseline study (60 patients) was maintained in 25 and lost in 35 patients postablation.Conclusion: These data suggest that: (1) dual pathway physiology may persist after successful ablation, which might be a reflection of multiple reentrant pathways in patients with AVNRT: and (2) the retrograde pathways during common and uncommon AVNRT have anatomically separate atrial breakthroughs. These findings have important electrophysiologic implications regarding the prevailing concept of the AV nodal physiology in patients with AVNRT.