Complete Atrioventricular Block and Permanent Pacemaker Implantation Following Percutaneous Coronary Intervention to Left Anterior Descending Artery Chronic Total Occlusion.

A 72-year-old male patient, with first degree atrioventricular block and LBBB on his baseline ECG, developed persistent complete atrioventricular block after recanalization of a chronic total occlusion of his left anterior descending artery (LAD) and ultimately underwent permanent pacemaker implantation. Occlusion of the second septal branch, probably supplying the right branch of the His bundle is speculated to have led to this complication. During elective intervention to the LAD territory in patients with prior conduction abnormalities on the ECG, care should be taken to preserve normal blood flow to the septal perforators. When a deterioration in septal perfusion occurs restoration of flow by wiring and balloon dilatation should be considered.