Résumé
The objectives of the present study were to evaluate the effects of left ventricular [LV] preload due to ventricular septal defect [VSD] on cardiac performance, and to compare the therapeutic effects of captopril versus propranolol on infants with hemodynamically significant large VSD with heart failure. The study included 60 infants with VSD, classified into: large VSD [20 infants], moderate VSD [20 infants] and small VSD [20 infants]. Twenty healthy infants served as a control group. All infants were subjected to history taking, clinical examination, X-ray chest and heart and echocardiographic evaluation [using conventional echo-Doppler and tissue Doppler imaging]. Follow up was done in infants with large VSD after 3 months of therapy for two subgroups: group A [10 infants treated with pro pranolol] and group B [10 infants treated with captopril]. The results showed LV diastolic dysfunction, but no systolic dysfunction in large VSD, with decreased EIA ratio [by pulsed transmitral Doppler] and decreased e/a ratio [by tissue Doppler]. The tissue Doppler was more sensitive than the pulsed Doppler [sensitivity 90%vs. 40%]. Comparing both drugs used in large VSD; propranolol led to significant clinical improvement [respiratory rate, heart rate and weight gain], whereas captopril led to significant hemodynamic improvement of LV myocardial function [ejection fraction and fraction shortening], LV diastolic function, decreased cardiomegaly [by X-ray], decreased size of VSD and significant decrease of pulmonary to systemic flow ratio [Qp/Qs] [P<0.05]. Conclusions: Tissue Doppler is more sensitive than pulsed transmitral Doppler in detecting LV diastolic dysfunction in infants with large VSD. Captopril improves the hemodynamics of large VSD with congestive heart failure and corrects the LV diastolic dysfunction, whereas propranolol improves the clinical manifestations with better weight gain before surgical repair