Echocardiographic indices of left ventricular function. A comparison.

Multiple M-mode echocardiographic indices of left ventricular function are currently in use, but their reliability is disputed. Therefore, we correlated echo ejection fraction (EF) using quadratic (Q) and cubic (C) formulae, percentage of minor axis shortening (%S), mean velocity of circumferential fiber shortening (mVCF), and peak VCF with angiographic EF in 37 subjects, including 10 normal subjects. None had echocardiographic segmental wall motion abnormalities. Significant linear correlations were found between angiographic EF and EFc (r = 0.78), %S (r = 0.77), EFQ(r = 0.68), peak VCF (r = 0.68), and mVCF (r = 0.58). However, for all indices, the scatter was too great to permit reliable quantitative estimations of angiographic EF based on echo date. Peak VCF was qualitatively the most reliable predictor of ventricular function, being greater than or equal to 2.00 circumference per second in 23 of 25 patients with angio EF greater than or equal to 55 percent and less than 2.00 circumferences per second in 11 of 12 with EF less than 55 (sensitivity [sens] 92 percent, specificity [spec] 92 percent). Mean VCF (sens 83 percent, spec 80 percent), %S (sens 50 percent, spec 96 percent), EFC (senc 58 percent, spec 96 percent), and EFQ (sens 58 percent, spec 92 percent) were less satisfactory. We conclude that echo indices are reliable only as qualitative parameters of ventricular function. Peak VCF appears to be the most sensitive and specific qualitative index now available.