Color-Doppler- directed echocardiographic technique for the evaluation of left ventricular diastolic filling: Validation by radionuclide angiography

A novel color-Doppler-directed echocardiographic technique was developed for the determination of left ventricular (LV) peak filling rate normalized to the end-diastolic volume (NPFR). To calculate this diastolic filling index, the mitral valve cross-sectional area (MVA) was measured using color Doppler inflow column width for guidance, and the LV volumes were determined by biplane Simpson's rule. For comparison, NPFR was measured in a similar fashion by a non-color Doppler echocardiographic (DE) technique with MVA determined on the gray scale image. Radionuclide angiography (RNA) was used as a reference standard. Thirty-two patients were considered for this study. Seven were excluded because of technical (5 cases) or pathophysiological reasons. The mean NPFR values for color DE, non-color DE and RNA were 2.14 ± 1.03, 2.83 ± 1.43 and 2.08 ± 1.43 s^-1, respectively. There was a fair correlation demonstrated between the non-color DE method and RNA (r= 0.60, SEE = 1.18 s^-1. On the other hand, an excellent correlation existed between the color DE method and RNA (r = 0.85, SEE = 0.55 s(^-1). This improvement was statistically significant (p < 0.05). In conclusion, the color DE method for determination of NPFR is more reliable than the non-color DE method in reproducing RNA results. However, DE techniques are considerably less applicable than RNA, because 22% of the patients successfully tested with RNA could not be studied with DE methods.