Assessment of Mitral Insufficiency Using Doppler Ultrasound

Abstract

Mitral insufficiency (M.I.) causes a relative increase in early svstolic aortic blood flow. The instantaneous aortic blood velocity was recorded transcutaneously using a 2.2 MHz nondirectional Doppler ultrasound unit focused at 8 cm. The transducer was positioned in the suprasternal notch and aimed posteriorly to cross the descending aortic arch approximately parallel to flow. ECG, phonocardiogram and carotid pulse were recorded simultaneously. In 17 normal patients the aortic velocity pattern was nearly symmetrical and by planimetry the % area in the first half of systole was 52±4%. Eighteen patients, 2 without and 14 with M.I., were studied by cardiac catheterization and Doppler ultrasound. Using angiographic left ventricular volume measurements and the Fick cardiac output the % regurgitation was calculated for each. In M.I. the transcutaneous aortic velocitv tracing showed a greater percentage area under the portion presenting the first half of systole, varying from 52% to 79% in these patients, and when plotted against the % regurgitation showed a significant correlation (r=0.88). M.I. can be accurately assessed by this noninvasive technique.