Catheter Ablation of Atrioventricular Nodal Re-entrant Tachycardia: Facts and Fiction

Abstract

Although the exact circuit of atrioventricular nodal re-entrant tachycardia (AVNRT) still eludes us, AVNRT is the most common regular arrhythmia in humans, and therefore the most commonly encountered during ablation attempts for regular tachycardias. [1][2][3][4] Catheter ablation for AVNRT is the current treatment of choice in symptomatic patients. It reduces arrhythmia-related hospitalisations and costs, and substantially improves quality of life. [5][6][7][8][9][10][11][12][13][14][15][16] Catheter ablation approaches aimed at the fast pathway have been abandoned; slow pathway ablation, using a combined anatomical and mapping approach, is now the method of choice. This approach offers a success rate of 95 %, has a recurrence rate of approximately 1.3-4.0 %, and has been associated with a low risk of atrioventricular (AV) block that in most, but not all, studies is <1 %. 9,10,15,17 How true are these assumptions, however, in the current era of catheter ablation? Recent reports have provided useful insights into the technique and complications associated with catheter ablation,and several myths have been refuted, outlined below. 5,[18][19][20] We know now that the inferior nodal extensions represent the anatomical substrate of the slow pathway in all forms of AVNRT. 4,[21][22][23] The only legitimate question that still remains unanswered is the relative importance of the right and left extensions. Connexin staining and genotyping studies have identified the left inferior extension and the AV node itself as areas of low connexin 43 (Cx43) expression, and consequently slow conduction, thus suggesting that this is the main substrate of the slow pathway (Figure 1). 24 The inferior nodal extensions at the inferior (posterior) part of the triangle of Koch and below the coronary sinus ostium, as depicted in the right anterior oblique projection, are the appropriate targets for KeywordsAtrioventricular nodal re-entrant tachycardia, catheter ablation Disclosure: The author has no conflicts of interest to declare.A. Proposed circuits of AVNRT based on the role of the inferior nodal extensions. During typical AVNRT (slow-fast) right-or left-sided circuits may occur with antegrade conduction through the inferior inputs and retrograde conduction through the superior inputs or the anisotropic atrionodal transitional area. In atypical AVNRT, conduction occurs anterogradely through the left or right inferior inputs, and retrogradely through the other. Depending on the orientation of the circuit, we may record the so-called fast-slow, slow-slow, or indeterminate types. B. Hypothetical circuits of AVNRT based on connexin genotyping data. Areas in blue have a high expression of Cx43 and therefore display characteristics of fast conduction. These are the right inferior extension, and the lower nodal bundle. There is also a smooth transition in Cx43 at the interface of the transitional cells and the node. Areas in yellow, such as the compact node and the left inferior extension, have very low Cx43 expression and are capable of slow...

JinJiang ablation catheter is no inferior than Johnson ablation catheter in radiofrequency ablation of paroxysmal supraventricular tachycardia

“…Such events including hemopneumothorax, puncture hematoma, third degree AV block, and cardiac tamponade have been reported in previous studies. [7][8][9] Based on our analysis, Jinjiang catheter ablation can effectively diagnose and treat routine PSVT, just like J&J catheter ablation.…”

Evaluation of the effects of isoproterenol on arrhythmia recurrence following catheter ablation in patients with atrioventricular nodal re‐entrant tachycardia: A randomized controlled clinical trial

“…Atrioventricular (AV) re‐entrant tachycardia (AVNRT) is considered the most common regular supraventricular arrhythmia (SVT) in children and adults, 1 , 2 whose standard treatment is catheter ablation of the slow pathway in the AV node. 3 Currently, the non‐inducibility of re‐entrant arrhythmia after the ablation with programmed electrical stimulation with or without provocative medication is a conventional method to ensure the desired result of ablation. 4 , 5 However, although each strategy has its proponents and opponents and is employed by professionals, there is still insufficient documentation for evidence‐based decision‐making in choosing a strategy for pharmacological or non‐pharmacological induction of arrhythmia after the ablation.…”

“…Atrioventricular (AV) re‐entrant tachycardia (AVNRT) is considered the most common regular supraventricular arrhythmia (SVT) in children and adults, 1,2 whose standard treatment is catheter ablation of the slow pathway in the AV node 3 . Currently, the non‐inducibility of re‐entrant arrhythmia after the ablation with programmed electrical stimulation with or without provocative medication is a conventional method to ensure the desired result of ablation 4,5 .…”