Assessment of Left Ventricular Function Using Pulsed Tissue Doppler Imaging in Healthy Dogs and Dogs with Spontaneous Mitral Regurgitation

Pulsed tissue Doppler imaging (pulsed TDI) has been demonstrated to be useful for the estimation of left ventricular (LV) systolic and diastolic functions in various human cardiac diseases. The objectives of this study were to investigate the relationship between pulsed TDI and LV function by using cardiac catheterization in healthy dogs and to evaluate the clinical usefulness of pulsed TDI in dogs with spontaneous mitral regurgitation (MR). The peak early diastolic velocity (E'), peak atrial systolic velocity (A'), and peak systolic velocity (S') were detectable in the velocity profiles of the mitral annulus in all the dogs. In the healthy dogs, S' and E' were correlated with LV peak +dP/dt and -dP/dt, respectively. E' was lower in dogs with MR than in dogs without cardiac diseases. E/E' in the MR dogs with decompensated heart failure was significantly increased in comparison with those with compensated heart failure. The sensitivity and specificity of the E/E' cutoff value of 13.0 for identifying decompensated heart failure were 80% and 83%, respectively. In addition, E/E' was significantly correlated with the ratio of left atrial to aortic diameter. These findings suggest that canine pulsed TDI can be applied clinically for estimation of cardiac function and detection of cardiac decompensation and left atrial volume overload in dogs with MR.