Noninvasive assessment of mitral insufficiency by transcutaneous Doppler ultrasound

Instantaneous aortic arch blood velocity was recorded transcutaneously from the suprasternal notch, using a 2.2 MHz Doppler ultrasound unit, in 18 normals and 16 patients undergoing cardiac catheterization who had murmurs of mitral regurgitation. In normals aortic blood velocity rose rapidly in early systole to a midsystolic peak then fell to zero velocity. These roughly parabolic patterns had area ratios beneath the first and second halves of the curves measuring 52:48 +/- 3 (SD). With increasingly severe mitral regurgitation the pattern became skewed leftward such that the percent in the first half of systole ranged from 53-79%. From the angiograms of our sixteen patients an estimate of true percent regurgitation was made using the Fick cardiac output and ventricular volume measurements. When compared with the area under the first half of the velocity curve a strong correlation was found (r = 0.84) indicating that this Doppler technique can be used to evaluate mitral insufficiency.