Myocardial infarction-induced ventricular aneurysm in the presence of complete left bundle branch block: a case report suggesting a new electrocardiographic diagnostic criterion.

A 65-year-old man who had suffered an anterior myocardial infarction (MI) 10 years ago, complicated by a ventricular aneurysm (VA), and subsequently many years later developed complete left bundle branch block (LBBB), is described, with main emphasis on the feasibility of the electrocardiographic (ECG) diagnosis of VA in the presence of this conduction abnormality. Ventricular aneurysm in our patient was repeatedly confirmed by echocardiography over the intervening years. During the time the patient maintained normal intraventricular conduction, the ECG showed persisting ST-segment elevations in the precordial leads. After the development of LBBB, the ECG displayed accentuated ST-segment elevations in the precordial leads with predominantly negative QRS complexes, and ST elevation in V5, despite its primarily positive QRS complex. The authors extend the findings from the previous literature on the diagnosis of acute MI in patients with LBBB or right intraventricular pacing, and the concept of primary and secondary repolarization changes, to the diagnosis of VA in the presence of LBBB.