Chapman's sign

Chapman’s sign is used to diagnose an acute myocardial infarction in the setting of a left bundle branch block and consists of a notch in the upslope of the R wave in lead I, aVL or V6. This has a low sensitivity, but a specificity of about 90%.

Determining the presence of an acute myocardial infarction when a patient has a baseline left bundle branch block present is difficult. Besides Chapman’s sign, the Sgarbossa criteria and the Cabrera's sign can be helpful.