To construct a neonatal rat model of increased right ventricular (RV) afterload for studying the pathophysiological remodeling of the right ventricle in patients with congenital heart disease with increased RV afterload.Methods:
Surgery was performed within 6 hours after birth. Horizontal thoracotomy was performed by dissecting the intercostal muscles and splitting the sternum. The PA was then banded with 11-0 nylon thread. At postnatal day 7 (P7), constriction of PA was confirmed by echocardiography. The RV systolic and diastolic pressures were measured by cardiac catheterization. The RV end-systolic volume, end-diastolic volume, end-diastolic diameter, and free wall thickness were assessed by magnetic resonance imaging. The histological changes in sham-operated and PA-banding (PAB) hearts were evaluated by hematoxylin and eosin staining.Results:
Increased RV afterload was established by constriction of the PA in neonatal rats within 6 hours after birth. The survival rate was 75% at P7. Relative to the sham group, the peak pressure gradient across the PA constriction and RV systolic and diastolic pressures, end-systolic volume, end-diastolic volume, end-diastolic diameter, and free wall thickness were significantly increased in the PAB group at P7 (P < .01). Consistently, histological examination showed that the RV free wall was significantly hypertrophic in the PAB group.Conclusions:
We successfully established a neonatal RV afterload increase model through PAB within 6 hours after birth, which can be used to study the pathophysiological changes in congenital heart diseases with increased RV afterload.