Assessment of left ventricular function before and after Fontan's operation for the correction of tricuspid atresia....

Functional change in the left ventricle was studied in the light of changes in the left ventricular (LV) volume preload before and after Fontan's operation. Six cases with tricuspid atresia (TA) were studied, and they had either types Ib or IIb. The preoperative LV end-diastolic volume index (LVEDVI) was 123 +/- 44 ml/m2, which corresponds to 166% +/- 45% of normal values. This suggests that in TA the preload of the LV volume is increased because of its peculiar hemodynamic situation. After Fontan's operation, the LVEDV decreased by 24.6% to 119.6 +/- 87.7 ml (P = 0.01), which corresponds to 120% +/- 50.9% of normal values. Presenting a striking contrast to the decrease in LVEDV, the postoperative reduction in LV end-systolic volume (LVESV) was approximately 8%. Preoperative and postoperative values for LVESV were 67.1 +/- 50.8 ml and 62 +/- 45.6 ml, thus, the systolic volume was decreased. Because of the small change in LVESV, the ejection fraction (EF) of the left ventricle significantly decreased from 0.61 +/- 0.1 preoperatively to 0.48 +/- 0.1 postoperatively. The cardiac index (CI) remained in the range of 1.9-2.5 l/min/m2 with a mean of 2.2 +/- 0.2 l/min/m2 at 1 month after operation. But, later, improvement in EF was observed in one case, in which the CI increased from 2.5 to 3.2 l/min/m2.(ABSTRACT TRUNCATED AT 250 WORDS)