Bifascicular block

Interpretation by Matthew Schumaecker
EKG recorded and edited by Dr. M. Rosengarten, MUHC, 1997

This tracing shows sinus rhythm at 82/minute. The PR interval is 180 ms. The QRS interval duration of 260 ms indicates a conduction defect. There is an M shaped QRS complex (rSR' variant) in leads V1 to V3. In addition there are S waves in leads I, aVL, V5 and V6. There are also prominent S waves proceeded and small r waves in II, III and aVF . The QRS has as a left axis deviation. These findings indicate the presence of a bifascicular block, right bundle branch and left anterior hemiblock..

The inverted T waves in V1 and V2 are probably due to the conduction disturbance and not ischemia.