Summary of Learning points Normal QRS duration = 60-100 msec Wide QRS = QRS duration > 120 msec (3 little boxes) Differential diagnosis...

Summary of Learning points Etiology of BBB Acute inflammation Ischemia/scar Infiltrative disease Left bundle branch block criteria QRS >...

Summary of Learning Points Cardiac Conduction: Sinoatrial (SA) node   atrioventricular (AV) node bundle of HIS and left/right bundle...

Summary of Learning Points “Irregularly Irregular” Rhythms Include Atrial Fibrillation and Atrial Flutter with variable conduction...