Effect of patent ductus arteriosus on doppler-derived right ventricular systolic time intervals

Right ventricular systolic time intervals (RVSTI) and noninvasive Dopplerderived pulmonary blood flow were measured before and after surgical ductus ligation in 18 otherwise healthy infants and children who were older than 3 months of age. Right ventricular preejection period (PEP) and the ratio of preejection period and right ventricular ejection time (PEP/REVET), both corrected or uncorrected for heart rate, decreased significantly following surgery (PEP 71±14 vs. 50±13, p<0.001 and PEP/RVET 0.29±0.06 vs. 0.21±0.05, p<0.001). The volume of pulmonary blood flow correlated with PEP/RVET (r=0.48, p=0.003). The magnitude of the change in pulmonary blood flow correlated with the change in PEP/RVET (r÷0.56, p=0.016). The velocity of circumferential fiber shortening (VCFc) increased after surgery, but not significantly. We speculate that patent ductus arteriosus has a similar effect on right ventricular performance when other congenital heart defects are present.