[Time analysis of mitral regurgitation in patients with mitral valve prolapse: a study by phonocardiography and Doppler techniques].

To assess the timing and duration of mitral regurgitation (MR) in patients with mitral valve prolapse (MVP), 20 subjects with mid-systolic click(s) and/or a late systolic murmur were studied using phonocardiography, two-dimensional echocardiography (2DE) and Doppler techniques including pulsed Doppler (PD), high pulse repetition frequency Doppler (HPRF), continuous wave Doppler (CW) and M-mode color Doppler (MD) methods and two-dimensional Doppler color flow mapping (2DD). The results were compared with those of 16 patients with a pansystolic murmur having late systolic accentuation. MVP with MR was observed in 15 of the 20 patients with mid-systolic clicks and/or a late systolic murmur and in all of the 16 patients with a pansystolic murmur. Using MD, MR signals were seen throughout systole and isovolumic relaxation period in all but one of these patients, and they were not related to the patterns of the systolic murmur. In only one, an MR signal was recorded just after the click. Five patients with a mid-systolic click lacked the findings of MVP, but two of them had MR signal only in early systole. Using PD and HPRF techniques, the timing and duration of MR signals in patients with mid-systolic clicks and/or a late systolic murmur were varied by changing the sites of the sample volume. Similarly, the timing and duration of MR signals in these patients were dependent on the ultrasonic beam direction by the CW method. In most patients with a pansystolic murmur having late systolic accentuation, however, MR signals throughout systole and the isovolumic relaxation period were demonstrated by each Doppler method. Therefore, PD, HPRF, and CW were not so efficiently sensitive or adequate techniques for investigating the timing and duration of MR, especially in patients with mid-systolic clicks and/or a late systolic murmur, who had mild or eccentric MR jets. In conclusion, 1) MR in MVP involves the entire systole and isovolumic relaxation period, 2) PD, HPRF and CW methods are not adequate for detecting mild or eccentric MR jets in patients with mid-systolic clicks and/or a late systolic murmur, and 3) MD is useful for the time analysis of MR in these patients.