An enhanced method for left ventricular volume and ejection fraction by triggered harmonic contrast echocardiography

To elucidate the validity and reproducibility of the use of intravenous ech o-contrast agent in the evaluation of left ventricular (LV) performance, we measured LV volume and ejection fraction (EF) in 42 patients with triggere d harmonic contrast imaging (THCI), compared with continuous harmonic imagi ng without contrast agent (CHI) and with cineventriculography (CVG). In 10 of 42 patients, THCI improved LV border delineation which could not be obta ined even with CHI. LV end-diastolic, end-systolic volumes and EF by both C HI and THCI correlated well with those by CVG. Although LV volumes are unde restimated, THCI lessened the mean differences to about in half, compared w ith CHI. The observer variabilities obtained using THCI were smaller than t hose by CHI. These results indicate the validity of LV enhancement and the measurement of EF using THCI. We suggest that this method noninvasively pro vides more accurate LV systolic function with the acceptable reproducibilit y.