Reversible Pulmonary Trunk Banding. XI: Myocardial Vascular Endothelial Growth Factor Expression of Young Goats Submitted to Rapid Ventricle Retraining

Introduction: Intermittent systolic overload proved to be superior to traditional PA banding, with a more efficient ventricle hypertrophy, even with less exposure to pressure overload. There is a great interest on the adaptive mechanisms of the retrained ventricle. Hypothesis: This study sought to assess vascular endothelial growth factor (VEGF) expression in the subpulmonary ventricle (RV) retraining of young goats submitted to continuous versus intermittent systolic overload. Methods: Twenty one21 young goats were separated into 3 groups: sham (no systolic overload), continuous (continuous systolic overload), and intermittent (four 12-hour periods of systolic overload paired with a 12-hour resting period). During a 96-hour protocol, systolic overload was adjusted to achieve a 0.7 right ventricle/aortic pressure ratio. Hemodynamic evaluations were performed before and after systolic overload every day in the postoperative period. Echocardiograms were obtained in the preoperative period and at the end of protocol. After the study period, the animals were humanely killed for morphologic and vascular endothelial growth factor (VEGF) expression assessment. Results: Both groups had increased right ventricular and septal masses compared with the sham group (P Conclusions: Intermittent systolic overload promotes a greater neoangiogenesis signaling. The association of RV hypertrophy and increased VEGF expression has important implication on the ability of the heart to adapt to pressure overload by promoting a compensatory growth of the coronary vasculature, allowing for a more efficient hypertrophy.