Anteroseptal myocardial infarction is defined by the presence of electrocardiographic Q-waves limited to precordial leads V(1) to V(2), V(3), or V(4). We sought to determine whether this term is appropriate by correlating electrocardiographic, echocardiographic, and angiographic findings. We studied 50 consecutive patients admitted for a first acute myocardial infarction with Q-waves in precordial leads V(1) to V(2)-V(4), and who had undergone echocardiography and coronary angiography during hospitalization. Echocardiograms in the apical long-axis, two-chamber, and four-chamber views were studied using a wall motion scoring index.Q-waves were present in precordial leads V(1)-V(2) in 4 patients, V(1)-V(3) in 28 patients, and V(1)-V(4) in the remaining 18 patients. The presumptive culprit lesion was in the proximal segment of the left anterior descending artery in 15 patients, in the middle segment in 33 patients, and indeterminate in 2 patients. This lesion was before the first septal branch in 19 patients and after the first septal branch in 29. Mean (+/- SD) left ventricular ejection fraction was 51% +/- 10%. Echocardiographic analysis showed that the septal wall was never the only wall that was affected. However, the apex was affected in all patients and was the only wall that was affected in 26 (52%) patients (apical wall index, 2.1 +/- 0.5). In the remaining 24 patients, the septum was also affected (septal index, 1.5 +/- 0.3), but less severely than was the apex (apical index, 2.3 +/- 0.4; P <0.0001 vs. septum). In these 24 patients, the anterior and lateral walls were also affected (anterior index, 1.4 +/- 0.4; lateral index, 1.1 +/- 0.2), but again, less severely than was the apex (P <0.0001 for both vs. apex). Neither angiographic nor echocardiographic data support the notion of an isolated anteroseptal myocardial infarction. Left anterior descending artery involvement appears more often to be midsegment and postseptal. The apex is always and principally affected. These findings suggest that anteroseptal myocardial infarction is a misnomer and that the V(1) to V(2)-V(4) Q-wave pattern should be considered to indicate a predominantly apical, and generally limited, myocardial infarction.