Electrocardiographic ST segment elevation: left ventricular aneurysm.

Left ventricular aneurysm (LVA), also described as dyskinetic left ventricular segment, is defined as a localized area of infarcted myocardium that bulges outward during both systole and diastole. LVAs most often are noted after large anterior wall events but may also be encountered status after inferior and posterior wall injuries. In most cases, LVA is manifested electrocardiographically by varying degrees of ST segment elevation (STE), which may be difficult to distinguish from ST segment changes caused by acute myocardial infarction. The STE is generally associated with well-developed, completed Q waves in the anterior precordial leads, and there will not be reciprocal ST depression in the contralateral leads. This article focuses on the electrocardiographic findings useful in making the diagnosis of left ventricular aneurysm as well as distinguishing LVA from other STE syndromes.