Search

The exercise ECGs of 30 patients with pure aortic regurgitation (AR) were compared with functional and geometric variables measured by echocardiography and radionuclide cineangiography. The 10 patients with positive ECG responses to exercise (greater than or equal to 0.1 mV additional downsloping or horizontal ST segment depression) were similar to the 20 patients with negative tests with respect to mean age, exercise duration, peak work load achieved, symptoms, and resting ECG findings. Patients with positive exercise tests had significantly reduced left ventricular (LV) ejection fractions at rest (44 +/- 4% vs 52 +/- 2%) and during peak exercise (38 +/- 3% vs 48 +/- 2%), lower fractional shortening at rest (27 +/- 1% vs 34 +/- 2%), higher end-systolic wall stress (150 +/- 18 vs 99 +/- 8 dynes/cm2 X 10(3], lower left ventricular relative wall thickness (0.26 +/- 0.01 vs 0.30 +/- 0.01), and greater end-systolic diameter (5.7 +/- 0.3 vs 4.5 +/- 0.2 cm) than patients with negative tests (p less than 0.05 for all comparisons). Among the 18 asymptomatic patients, positive tests were associated with lower resting fractional shortening, lower exercise ejection fraction, higher wall stress, and greater end-systolic diameter. These data demonstrate that a positive exercise ECG in aortic regurgitation identifies patients, even when asymptomatic, who have developed markedly abnormal left ventricular functional and geometric responses to volume load, while a negative exercise ECG identifies a subset of asymptomatic patients who are unlikely to have severe ventricular dysfunction.

To evaluate the relation of aortic root dilatation to aortic regurgitation, we examined clinical, echocardiographic, and radionuclide cineangiographic findings in 102 patients with severe aortic regurgitation. Aortic root dilatation was the only apparent cause in 31 patients (30%), exceeding in prevalence any valvular cause, and was independently associated only with older age (p less than 0.001). Echocardiography showed dilatation to be either localized to the sinuses of Valsalva or to be generalized. At initial evaluation, patients with generalized dilatation had severer abnormalities of left ventricular size and function than those with localized or no dilatation. Aortic valves were subsequently replaced in more patients with generalized than localized dilatation during 28 +/- 17 month follow-up (9 of 15 patients compared with 2 of 15, p less than 0.03). Thus, idiopathic aortic root dilatation is the commonest definable cause of severe aortic regurgitation; aortic root dilatation is associated independently with age but not blood pressure; and generalized aortic root dilatation is associated with marked ventricular dilatation, hypertrophy, and dysfunction.