QUANTITATIVE STRESS ECHOCARDIOGRAPHY IN CHRONIC AORTIC AND MITRAL REGURGITATION

It was the purpose of the present study to prove the feasibility and r eliability of quantitative stress-echocardiography as an alternative m ethod to radionuclide angiography (RNA) in chronic regurgitant valvula r lesions. Echocardiography and RNA are most commonly used to obtain v arious left ventricular (LV) morphometric and functional parameters th at have been postulated to predict long-term prognosis in patients wit h aortic and mitral valvular regurgitation. Supine bicycle ergometry w ith a workload ranging from 25-250 Watts was used to evaluate stress d ependent LV volumes and ejection fractions (EFs) in patients with pure aortic (n = 18) and mitral regurgitation (n = 14). Most patients (23/ 32) underwent simultaneous right heart catheterization. Echocardiograp hic EFs were validated by RNA with good correlations (r = 0.81, P < 0. 01). Patients with aortic regurgitation and functional class I/II (9), had a significant increase in EF during exercise (60%-67%, P < 0.001) and a reduction in end-systolic volume (71-52 mt, P < 0.01). In compa rison, patients with class III symptoms (9), had a drop in EF (53%-49% , P < 0.01), had lager baseline end-systolic volume (104 mL, P = NS), which did not decrease during stress (104 vs 107 mt, P = NS). In patie nts with chronic mitral regurgitation baseline and exercise EF did not differ between class I/II (6) and class III (8), however, mildly symp tomatic patients increased from 57%-67%, (P < 0.01) versus patients in class III (65% vs 69%, P = NS). Stroke volume index: was not differen t at baseline (44 vs 33 mL/m(2), P = NS); however, there were signific ant differences during exercise (70 vs 41 mL/m(2), P = 0.05). Quantita tive stress-echocardiography is a noninvasive and safe alternative met hod to RNA, which allows reliable calculation of stress dependent LV v olumes and EF. Determination of end-systolic volumes may be of additio nal prognostic value. The combination of a high baseline EF and low st roke volume index with the inability to improve during exercise might reflect early stages of impaired LV function in patients with severe m itral regurgitation.