ECG Library

Save

All ECG 11

The ECG shows normal sinus rhythm at 75 beats per minute with a prolonged PR interval of 0.24 sec, ie, first-degree atrioventricular block. The QRS duration is about 0.16 sec with a left bundle branch block (LBBB) morphology. There is distinct notching at 40 msec in the upslope of the S wave in lead V3 and V4. This is Cabrera’s sign, which may occur with an acute myocardial infarction (MI) in the setting of LBBB. Cabrera’s sign has low sensitivity (27%) for MI.

Click the Left Bundle Branch Block review below for details. Related: Left Bundle Branch Block ECG Review, First-Degree Atrioventricular Block ECG Review