Abstract
The digital stethoscope has made it possible to record and visualize heart sounds. In this study, we examined whether there was a correlation between heart sounds and the severity of mitral regurgitation (MR) using seven healthy dogs and twenty dogs with MR. The ratio of the first heart sound frequency to the second heart frequency (heart sound frequency ratio), and the diameter ratio of the left atrium to the aorta (LA/Ao) were calculated; early diastolic mitral flow (E) and early diastolic lateral mitral annulus velocity (E’) were measured simultaneously, and E/E’ was calculated. The heart sound frequency ratio in the MR dogs was significantly correlated with LA/Ao, E, and E/E’ (p<0.01, in each case), and the MR dogs tended to show elevation of the heart sound frequency ratio. Since the severity of MR can be evaluated more quantitatively by analyses of heart sounds with the digital stethoscope than by conventional phonocardiography, the digital stethoscope is considered to be especially useful in small animal clinics.
