Complete Heart Block Induced During Cardiac Catheterization of Patients with Pre-existent Bundle-Branch Block

Abstract
The hazard of complete atrioventricular block during cardiac catheterization of patients with pre-existent bundle-branch block is described. A catheter-induced bundle-branch block, during catheterization of the ventricle opposite that which was already the site of bundle-branch block, would produce complete heart block in the form of bilateral bundle-branch block. Five patients in whom this complication occurred are described.