Coronary atherosclerosis is associated with left ventricular dysfunction and dilatation in aortic stenosis. Patients with aortic stenosis develop widely variable patterns of left ventricular hypertrophy and dysfunction. We postulated that coronary atherosclerosis (CAD) may be associated with impaired left ventricular function and chamber dilatation in patients with aortic stenosis. Left ventricular mass and volumes were quantified from two-dimensional echocardiography and correlated with coronary angiography in 78 patients with severe aortic stenosis and no previous myocardial infarction or regional wall motion abnormalities. Eighteen patients (group 1) had smooth coronary arteries, 25 patients had irregular coronary arteries with 50% or less stenosis (group 2), and 35 patients had obstructive CAD (group 3). Even though the calculated valve area was similar in all three study groups, group 1 patients had higher values for ejection fraction (65 +/- 9%, 51 +/- 17%, and 48 +/- 13%; p = 0.0002), systolic mass-to-volume ratio (9.2 +/- 3.9, 5.6 +/- 2.8, and 5.2 +/- 2.2; p = 0.0001), and cardiac index (2.9 +/- 0.7, 2.5 +/- 0.7, and 2.3 +/- 0.6 l/min.min2; p = 0.015) than patients in groups 2 and 3, respectively (mean +/- SD). Mean circumferential wall stress was inversely related to severity of CAD. Multivariate analysis showed that CAD is an independent predictor of ejection fraction and mass-to-volume ratio in this group of patients. Thus, in an elderly population with severe aortic stenosis, patients with both obstructive and nonobstructive CAD have an increased incidence of left ventricular enlargement and systolic dysfunction. 