Cabrera’s sign is used to diagnose an acute myocardial infarction in the setting of a LBBB or paced rhythm. This ECG sign was first described by Cabrera & Friedland in 1953.
It is defined as a prominent notching of at least 0.04 sec in the ascending limb of the S wave in any of leads V3-V4.
Although specificity is high, sensitivity for myocardial infarction is only 27% overall, 47% for anteroseptal MI.
ECG 1 Cabrera sign in V3,V4