MITRAL REGURGITATION Quantitation of mitral regurgitation by Doppler echocardiography

The evaluation and care of patients with mitral regurgitation would be facilitated by an easy, reproducible and noninvasive method that could quantitate the hemodynamic burden. In this study, we describe a new Doppler echocardiographic method that measures the regurgitant fraction and we compare it with angiographic and scintigraphic methods. A total of 27 patients with mitral regurgitation were evaluated by echocardiography and either cardiac catheterization or scintigraphy. With two-dimensional echocardiography, diastolic and systolic volumes were measured to derive the left ventricular stroke volume (LVSV). The forward stroke volume (FSV) was obtained from the product ofM mode-derived aortic valve area and ascending aortic flow velocity integral assessed by continuous-wave Doppler. Regurgitant fraction was calculated as follows: (LVSV FSV)/LVSV. Comparisons showed that regurgitant fraction calculated by Doppler echocardiography correlated with regurgitant fraction determined by both cardiac catheterization (r = .82) and by scintigraphy (r = .89). There was, however, an important interobserver variability within each method: 10%, 13%, and 11% for Doppler echocardiography, angiography, and scintigraphy, respectively. In conclusion, Doppler echocardiography can be used to quantitate mitral regurgitation. Serial noninvasive determinations of regurgitant fraction may be useful in the evaluation of therapy and in the follow-up of patients with mitral insufficiency. Circulation 74, No. 2, 306-314, 1986. MITRAL REGURGITATION is a common valvular lesion often leading to excessive ventricular dilatation and dysfunction, and the timing of surgical intervention is frequently difficult and controversial.1-' In such patients, a major determinant of myocardial size and function is the severity of regurgitation. An accurate noninvasive method for its quantitation would be desirable. The development of ultrasonic Doppler techniques has permitted noninvasive analysis of the dynamics of intracardiac flow.4'5 By means of pulsed Doppler echocardiography, valvular regurgitation can be identified68 with great sensitivity and specificity.9'6 Although the degree of regurgitation can be estimated qualitatively by Doppler mapping of the regurgitant From the Cardiovascular Division of the Department of Medicine, the John Henry Mills Echocardiography Laboratory, and the Cardiovascular Research Institute, University of California, San Francisco. Supported in part by a grant from the Fannie Ripple Foundation, Madison, NJ. Dr. Bouchard was supported by grant 830556 from the Quebec Health Research Foundation, Quebec, Canada. Address for correspondence: Alain Bouchard, M.D., Division of Cardiovascular Disease, Tinsley Harrison Tower, 311 University Station, Birmingham, AL 35294. Received June 6, 1985; revision accepted April 24, 1986. 306 flow in the left atrium, both overestimation and underestimation occur frequently.9 16 At the present time, optimal determination of the severity of valvular regurgitation requires angiographic quantitation of regurgitant flow. This is based on a comparison of left ventricular stroke volume, determined by biplane angiography, and forward flow, determined by the Fick or indicator dilution technique. In this report we describe the application of a new noninvasive Doppler echocardiographic method for quantitation of mitral regurgitation. The method compares the left ventricular stroke volume, obtained from biplane two-dimensional echocardiograms, with forward stroke volume, determined from the integral of the blood flow velocity in the ascending aorta obtained by continuous-wave Doppler and aortic valve area obtained by M mode echocardiography. The volume of regurgitation expressed as regurgitant fraction was compared with that measured at angiography and by the scintigraphic method.