Coronary Morphology and Conduction System Disturbance Induced by Therapeutic Embolization of the Coronary Septal Artery

Abstract

Percutaneous transluminal septal myocardial alcohol ablation (PTSMAA) is not a procedure without complications. It may produce heart arrhythmias, especially those due to disturbances of atrioventricular (AV) and interventricular (IV) electrical conduction. The goal of this study was to evaluate the relationship between the anatomical patterns of the right coronary artery and the left anterior descending artery (LAD) and to relate them to the AV and IV bundle branch blocks provoked by PTSMAA. Twenty patients with obstructive hypertrophic cardiomyopathy resistant to treatment with drugs successfully underwent PTSMAA. Electrocardiographic analyses were done before and after PTSMAA, and the results were compared with the abnormal septal anatomy. The effectiveness of PTSMAA was obtained in 18 (90%) of the 20 patients by ethanolization of the first great septal branch. In the other 2 patients (10%), 2 septal branches underwent alcoholization. First-grade temporary AV block (AVB) was observed in 6 patients (30%). Ten patients experienced severe bradycardia due to total AVB that required a temporary pacemaker, but 3 of the patients (15%) required a permanent pacemaker. Fourteen patients (70%) experienced permanent complete right branch block, and 2 developed incomplete left anterior block and incomplete left posterior block. Six patients presented with no electrical conduction disturbance at all. According to the results of the present investigation with the AV node artery derived from the right coronary artery in all cases, complete and permanent AV conduction system blockade occurred after PTSMAA in all types of anatomy regarding the observed LAD.