Diagnosing acute myocardial infarction (AMI) in left bundle branch block (LBBB) is challenging. Modified Sgarbossa criteria are known to help detect AMI in LBBB. This is a report about an electrocardiogram (ECG) with Wellens' signs in combination with a pre-existing LBBB. The ECG of a patient with fluctuating chest pain showed very subtle and one day later more obvious Wellens'signs. A left anterior descending artery (LAD) stenosis was diagnosed and successfully treated. Wellens' syndrome can be diagnosed in a case of LBBB and help detect a high-grade LAD stenosis even if modified Sgarbossa criteria are not met.
Keywords: Anterior wall myocardial infarction; ECG; Left anterior descending artery stenosis; Left bundle branch block; Wellens’ syndrome.