QRS duration of > 120 milliseconds rsR' "bunny ear" pattern in precordial leads Slurred S waves in leads I, V5, and V6. Remember that T wave inversions and ST segment depression is normal in leads V1 ...

Q: I recently had an electrocardiogram as part of a routine physical exam. The report said I had a bundle branch block. What does that mean? Will I need a pacemaker? A: Bundle branch blocks are ...

This ECG shows atrial fibrillation with an uncontrolled ventricular rate. There are two QRS complexes that become wide in a right bundle branch block pattern. This can occur at fast heart rates when ...

Correspondence to Dr Jonathan A Drezner, Stadium Sports Medicine Center, University of Washington, Seattle, WA 98195, USA; jdrezner{at}uw.edu The most substantive change is the introduction of a ...