DISCUSSION
atrioventricular block, arrhythmias, heart failure
ATRIOVENTRICULAR BLOCK, ARRHYTHMIAS, HEART FAILURE, COMPLICATION
The main finding from this study is that there was no significant difference in the RF ablation time required to induce atrioventricular block between retrograde left and anterograde right‐sided approaches.Ablation of the atrioventricular node is an effective treatment for symptomatic AF and also to achieve maximal cardiac resynchronization therapy in heart failure patients.The proximity of the atrioventricular node to the left‐sided endocardium has been suggested from previous studies in patients who have failed right‐sided ablation. Its proximity to the left‐sided endocardium has been shown in cases in which inadvertent atrioventricular block has been induced while ablating other left‐sided arrhythmias.Anatomically the common stem of the His bundle is comprised of a nonbranching and branching portion.Thus, recording His potentials below the aortic valve and between the noncoronary cusp along the membranous septum is achievable. Indeed, in a beagle animal study, Cheng et al.Souza et al.In this study, the procedure and fluoroscopy time was significantly greater in those randomized to left‐sided ablation compared to those commencing with a right‐sided approach. This is most likely due to the fact that there was a greater number of crossovers from the left to the right side. Three of the crossovers were performed before any RF was performed due to an unstable catheter position and in one case the operator was unable to cross the aortic valve despite repeated attempts. These procedures had the highest fluoroscopy and procedure times in the entire population studied and thus led to a higher‐than‐expected fluoroscopy and procedure time in the left‐sided group.More recently, Yorgun et al.One possible cause for the different results seen in this study is that the average age of the patients in the left‐sided cohort was 77.00 ± 5.17 years, which is older than the populations reported by Souza et al.We report a higher complication rate than Yorgun et al.In a clinical pathological study of patients who had undergone right and left‐sided atrioventricular ablation, Rizzo et al.In the current study, crossover from right‐sided to left‐sided ablation was permitted after six RF applications. Previous studies have suggested a crossover from the right side to the left side after 3 applications or even up to 10–15 applications.