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 ...

Impulses, or electrical signals, travel through both the left and right chambers of your heart to make it pump. But if the pathway is blocked, the impulses may move slower than normal or irregularly.

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 ...

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 ...