The diagnosis of mitral valve prolapse (MVP) still lacks a rigorous definition
by standard criteria which take into account the complete set of investigative
methods available. We did a comparative study of noninvasive methods,
including our technique of quantitative esophageal phonocardiography
(ePCG). A group of 40 patients who previously had a diagnosis of MVP by
M-mode echocardiography took part in the study. These patients were examined
by two-dimensional echocardiography (2D-echo) and Doppler echocardiography,
immediately followed by auscultation, ePCG and a conventional
phonocardiogram (ePCG). In 9 cases the M-mode diagnosis was dubious;
none of these had any other sign of MVP. In 18 cases MVP was confirmed by
2D-echo, 13 of them with mitral regurgitation (MR) according to the Doppler
study. All 18 cases were identified as MVP in the ePCG by the presence of a
midsystolic click (MSC, n = 2), a late systolic murmur (LSM, n = 3), or both
(n = 13). Moreover, 3 cases classified as negative by 2D-echo and Doppler
were found positive (MSC + LSM) for MVP by ePCG. Auscultation revealed a
MSC (n = 3), a LSM (n = 5), or both (n = 5) in 13 of the 18 2D-echo-positive
cases; in addition in 1 of the 2D-echo-negative cases a LSM was heard. The
ePCG was positive by MSC (n = 3), LSM (n = 4) or both (n = 4) in 11 of the 18
cases. ePCG thus proved to be more sensitive in diagnosing MVP than auscultation
and ePCG, and even than 2D-echo plus Doppler. In 2 of the 3 ‘overdiagnosed’
cases, where the ePCG was positive and 2D-echo and Doppler
were not, there was other evidence for a diagnosis of MVP.