Assessment of cardiac performance by first pass radionuclide angiocardiography in infants and children with normal heart and endocardial fibroelastosis.

Peak to peak time from the right and to the left ventricle (PPT), left ventricular ejection fraction, left ventricular peak ejection rate and left ventricular peak filling rate were measured by first pass radionuclide angiocardiography in 27 infants and children with normal heart and in 8 patients (18 studies) with endocardial fibroelastosis. In normal subjects, the PPT significantly correlated with heart rate (r = -0.87, p less than 0.001). A PPT corrected by the heart rate (cPPT) was calculated by rotation of the regression equation relating the variables: cPPT = PPT + 0.018 X (heart rate)-2.1. The cPPT averaged 3.0 +/- 0.0 (mean +/- S.E.) sec. Consequently, there was no significant correlation between the cPPT and heart rate, but the cPPT and body surface area are significantly correlated (r = 0.41, p less than 0.05). Left ventricular ejection fraction, peak ejection rate and peak filling rate averaged 68 +/- 2%, 4.2 +/- 0.3/sec and 4.8 +/- 0.3/sec, all of which were independent of the heart rate and body surface area. In patients with endocardial fibroelastosis, the cPPT was prolonged (4.7 +/- 0.4 sec), and left ventricular ejection fraction, peak ejection rate and peak filling rate were all reduced (28 +/- 4%, 1.7 +/- 0.2/sec and 1.8 +/- 0.2/sec). These results indicate that parameters obtained from the radionuclide angiocardiography are useful for evaluating cardiac performance in patients with endocardial fibroelastosis.