<qa>  What is the LBBB?- Cardiac conduction abnormalities denoted by any of the following: Evidence of second-degree type II or third-degree atrioventricular block, Evidence of ventricular pre-excitation, Electrocardiographic evidence of complete left bundle branch block LBBB, Intraventricular conduction delay with QRS duration 120 msec, Atrial fibrillation, Presence of cardiac pacemaker. 