Selective Radiofrequency Catheter Ablation of the Slow Pathway for Common and Uncommon Atrioventricular Nodal Reentrant Tachycardia.

Abstract

SUMMARYThe utility of selective radiofrequency catheter ablation of the slow pathway for the treatment of common and uncommon atrioventricular nodal reentrant tachycardia (AVNRT) was studied in 110 consecutive patients, 94 with slow-fast form common AVNRT, and 11 and 5, respectively, with the fast-slow and slow-slow forms of uncommon AVNRT. Ablation sites were determined by mapping a late and spiky "slow pathway potential" in the posterior right atrial septum in common AVNRT, and also the earliest retrograde atrial activation over the retrograde slow pathway in uncommon AVNRT. AVNRT was successfully eliminated in all patients with a mean number of radiofrequenc pulses of 2.93.0 and a mean total energy applied of 35362996 joules. There were no early or late complications, except for transient AV block for 15 sec immediately after energy application in one common AVNRT patient, and no recurrence of AVNRT in a mean follow-up period of 2413 months. There were no significant differences between common and uncommon AVNRT in success rate, mean application number and total energy applied. However, the AVN physiology post-ablation was different. Slow pathway conduction was eliminated in only 32% of the patients post-ablation in common AVNRT, while it was eliminated in 100% in uncommon AVNRT.Selective radiofrequency catheter ablation of the slow pathway can cure common and uncommon AVNRT effectively and safely. Common AVNRT can be eliminated irrespective of the persistence of slow pathway conduction, while uncommon AVNRT can be eliminated by the eradication of slow pathway conduction.

Role of Isoproterenol in Predicting the Success of Catheter Ablation in Patients with Reproducibly Inducible Atrioventricular Nodal Reentrant Tachycardia

“…The proportion of women (72.5%) in the current study was consistent with those of other series (62%-79%), [3][4][5][6][7][8][9][10][11]13 and there was no statistically significant difference between our 2 study groups in that regard (Table I). Female sex has been associated with higher recurrence rates.…”

“…1,2 Routinely after slow-pathway ablation, attempts at reinduction of arrhythmia are performed, with or without isoproterenol or other provocative medications. Some physicians use isoproterenol after ablation regardless of its use before ablation (strategy 1), [3][4][5][6][7] whereas others use isoproterenol after ablation of AVNRT only when it had been necessary for arrhythmia induction before ablation (strategy 2). [8][9][10][11][12] However, the published data available for the comparison of these 2 strategies are inadequate.…”

“…Some physicians consider the slow pathway to be successfully ablated only if AVNRT is not inducible both in the basal state and during isoproterenol infusion, regardless of how it was induced before ablation (strategy 1). [3][4][5][6][7] Others assume that the infusion of catecholamines is unnecessary after ablation, in cases wherein AVNRT is inducible in the basal state before ablation (strategy 2). [8][9][10][11][12] Neither group, however, has sufficiently examined the reproducibility of the arrhythmia, and both ignore the potential effect of reproducibility on the acute or longterm results of AVNRT ablation.…”

“…[8][9][10][11][12] Neither group, however, has sufficiently examined the reproducibility of the arrhythmia, and both ignore the potential effect of reproducibility on the acute or longterm results of AVNRT ablation. [3][4][5][6][7][8][9][10][11][12] Weismuller and colleagues 13 studied reinduction of AVNRT after ablation in the basal state in comparison with reinduction during the infusion of orciprenaline as a β-adrenergic stimulator. Of 121 patients with AVNRT who underwent successful ablation without sequela, 95 had inducible arrhythmia in the basal state.…”

Meta‐Analysis to Assess the Appropriate Endpoint for Slow Pathway Ablation of Atrioventricular Nodal Reentrant Tachycardia

“…The 10 studies used in the final analysis were published between 1992 and 2007 (Table I). 2,[4][5][6][7][8][9][10][11][12] The total number of patients was 1,204 and the mean follow-up was 1.9 years. The outcome of interest was the recurrence rate.…”