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Effect of patent ductus arteriosus on Doppler-derived right ventricular systolic time intervals
G M Silberbach1, R L Imus, R W McDonald
1Division of Pediatric Cardiology, Oregon Health Sciences University, Portland 97201.
Insights
Surgical closure of patent ductus arteriosus in children significantly improved right ventricular performance, indicated by reduced right ventricular systolic time intervals (RVSTI). This suggests PDA impacts RV function, even without other congenital heart defects.
Area of Science:
- Pediatric Cardiology
- Cardiovascular Physiology
- Congenital Heart Disease
Background:
- Patent ductus arteriosus (PDA) can affect cardiovascular hemodynamics.
- Understanding its impact on right ventricular (RV) function is crucial for pediatric cardiac care.
Purpose of the Study:
- To evaluate the effect of surgical ductus ligation on right ventricular systolic time intervals (RVSTI) and pulmonary blood flow in infants and children older than 3 months.
- To explore the relationship between RVSTI and pulmonary blood flow post-surgery.
Main Methods:
- Noninvasive Doppler echocardiography was used to measure RVSTI and pulmonary blood flow.
- Measurements were taken before and after surgical closure of PDA in 18 patients.
- Analysis included corrected and uncorrected heart rate values for PEP and PEP/RVET.
Main Results:
- Following surgical ductus ligation, significant decreases were observed in right ventricular preejection period (PEP) and the PEP/RVET ratio.
- Pulmonary blood flow volume showed a significant correlation with the PEP/RVET ratio (r = 0.48, p = 0.003).
- The change in pulmonary blood flow correlated with the change in PEP/RVET (r = 0.56, p = 0.016).
Conclusions:
- Surgical closure of PDA positively impacts RV performance in children.
- RVSTI, particularly the PEP/RVET ratio, serves as a useful noninvasive indicator of RV function and pulmonary blood flow.
- PDA may exert similar effects on RV performance even in the presence of other congenital heart defects.
Abstract:
Right ventricular systolic time intervals (RVSTI) and noninvasive Doppler-derived 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/RVET), 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 divided by 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.