Complete Heart Block Occurring during Cardiac Catheterization in Patients with Preexisting Bundle Branch Block

A case of catheter-induced complete heart block in a patient with preexistent left bundle branch block is documented by His bundle recordings. It is recommended that a temporary pacemaker catheter on demand should be placed in the right ventricular apex in all patients with complete bundle branch block undergoing cardiac catheterization. In the coronary care units catheters should never be passed blindly to the right heart chambers in patients with left bundle branch block.