[Diagnosis and estimation of mitral regurgitation by two-dimensional pulsed Doppler echocardiography]

The sensitivity and specificity of detecting and estimating mitral regurgitation were assessed by two-dimensional pulsed Doppler echocardiography (PDE) for 85 patients, aged 17 to 79 years. Mitral regurgitation was clinically diagnosed in 10 patients, and confirmed by angiography in 60 patients. Using real time two-dimensional images and M-mode displays, the sample volumes were taken at 36 sites, including the mitral ostium, the left atrium, and the left ventricular inflow tract. Doppler signals were analyzed by the FFT method and the diagnosis of mitral regurgitation was based on the systolic turbulence with a wide range of velocities greater than +/- 1 KHz. The results obtained were as follows: In 61 of 70 cases with mitral regurgitation, distinctly abnormal systolic Doppler signals were detected at the mitral ostium or within the left atrium, which were not recorded in the other 15 cases without angiocardiographically documented mitral regurgitation. The signals had either unidirectional or bidirectional wide frequency-band patterns, which were thought to indicate the systolic turbulence caused by mitral regurgitation, because these were occasionally recorded beyond the second heart sound, and increased with the administration of methoxamine and diminished after the inhalation of amyl nitrite. When mitral regurgitation was graded I degree, II degree, III degree and IV degree based on Sellers' classification, a PDE sensitivity for detecting mitral regurgitation was 78.1, 89.5, 100 and 100%, respectively. When approaches were divided by the parasternal long-axis, parasternal short-axis and apical long-axis, a PDE sensitivity was 80.0, 74.2, and 70.0%, respectively. The PDE was highly sensitive in diagnosing mitral regurgitation due to rheumatic valvular disease, mitral valve prolapse or ruptured chordae tendineae (sensitivity 100%), but it was less sensitive in ischemic heart disease, dilated cardiomyopathy or hypertrophic cardiomyopathy. Nine cases in which mitral regurgitation was missed by PDE, mitral regurgitation was mild (seven cases: Sellers I degree, two cases: Sellers II degree). No false positives were found. The overall sensitivity of the PDE was 87.1%, with a specificity of 100%, a diagnostic accuracy of 89.4%, and a predictive value of 100%. By displaying the distribution of systolic turbulence on parasternal or apical long-axis image (flow mapping), the direction and the extent of the regurgitant flow in the left atrium were clearly visualized. The localization of the regurgitant flow at the mitral ostium was visualized in parasternal short-axis images by the flow mapping method.(ABSTRACT TRUNCATED AT 400 WORDS)