Resumption of Right Atrial Isthmus Conduction Following Atrial Flutter Radiofrequency Ablation

Abstract

BRU, P., ET AL.: Resumption of Right Atrial Isthmus Conduction Following Atrial Flutter Radiofrequency Ablation. Right atrial isthmus block is currently accepted as a success criterion of atrial flutter ablation. An electrophysiological study performed days after the ablation procedure may show recovery of con duction across the isthmus in some patients, followed by arrhythmia recurrence. However, few data are available on the time course of this recovery and on the monitoring of isthmus conduction at the end of the ablation procedure as a means of increasing the success rate of the procedure. Radiofrequency (RF) catheter ablation was performed in 28 men and 7 women (mean age = 65 ± 11 years] presenting with com mon or clockwise atrial flutter (AFL) resistant to 2.9 ± 1.8 antiarrhythmic drugs. Underlying heart disease was present in 13 patients. The ablation procedure was performed with an 8-mm-tip catheter, by several 45-second applications at a target temperature of 65°C, directed to the isthmus between tricuspid annulus and inferior vena cava. Bidirectional isthmus block (BDB) was created with 4-24 RF applications in all but one patient. Special attention was paid to exclude incomplete block by meticulous mapping dur ing pacing at the coronary sinus os and at the low lateral right atrium every 5 minutes for 20 minutes there after. Conduction recovered across the isthmus in 5 patients at 10, 10,12,15, and 16 minutes, respectively, and further RF applications were needed to obtain stable block. At a follow-up of 17 ±10 months, AFL oc curred in the patient without, and in one patient with BDB. Thirty-three of the 34 patients (97%) with per sistent BDB remained free of arrhythmia recurrence. This study showed that conduction resumed across the isthmus within 20 minutes, after AFL ablation in 15% of the patients. The long-term results of the pro cedure can be optimized by ascertaining the persistence of BDB during that period of time. (PACE 2000; 23[Pt. Π]:1908 23[Pt. Π]: -1910 atrial flutter, radiofrequency ablation, isthmus conduction block

Effect of Isthmus Anatomy and Ablation Catheter on Radiofrequency Catheter Ablation of the Cavotricuspid Isthmus

“…The status of the bidirectional block was assessed continuously over the 30-minute period after bidirectional block occurrence. Thirty minutes after the bidirectional block was validated, 18 all patients underwent a postablation control by burst pacing at cycle lengths as short as 180 ms. On occasion, conduction resumed after ablation, which reinitiated a complete RFA sequence until the bidirectional block could be observed again, resetting the 30-minute waiting period. A cumulative time of RF delivery was recorded, and fluoroscopy time was calculated as total fluoroscopy time used for catheter positioning and RFA, including time to proof of bidirectional block.…”

Modification of the Unipolar Atrial Electrogram as a Local Endpoint During Common Atrial Flutter Ablation

“…Irrespective of the group, the procedure global endpoint was the achievement of a bidirectional block across the CTI, established by the following criteria: 1) clockwise block along CTI ablation site was validated by the recording of split double potentials (>90 ms) separated by an isoelectric segment during pacing from proximal CS; and 2) counter‐clockwise block along CTI ablation site was validated by the decrement in the timing of the terminal atrial component during differential pacing from the low to the high RA . Of note, if bidirectional block status was maintained over 20 minutes after the last RF application, the procedure was deemed successful …”

Interest of waiting time for spontaneous early reconnection after cavotricuspid isthmus ablation: A monocentric randomized trial

“…However, despite these validation methods, several studies and national registries suggest that RF ablation of AFl is still associated with a 10% recurrence rate . Most of these recurrences are associated with very early CTI conduction recovery after RF application . Despite the lack of any long‐term study with clinical follow‐up, it is currently recommended to observe a period of 30 minutes after RF application in order to check for early reconduction and reablation if necessary …”

“…Most of these recurrences are associated with very early CTI conduction recovery after RF application . Despite the lack of any long‐term study with clinical follow‐up, it is currently recommended to observe a period of 30 minutes after RF application in order to check for early reconduction and reablation if necessary …”