Early Outcomes of Right Ventricular Pressure and Volume Overload in an Ovine Model

Right ventricular (RV) failure is a common complication in multiple congenital heart disease (CHD), significantly increasing morbidity and mortality. Despite its impact, no therapies specifically target the failing RV. The growing population of CHD patients underscores the need to understand the pathophysiology of RV failure through preclinical research. This study aimed to develop an ovine model of RV failure induced by pressure and volume overload. A total of 14 juvenile sheep randomly underwent pulmonary artery banding (<i>n</i> = 6), pulmonary leaflet perforation (<i>n</i> = 4), and pulmonary annulotomy with transannular patching (TAP) (<i>n</i> = 4). Detailed anesthetic and surgical protocols were described, and intraoperative and early postoperative complications were evaluated. Acute RV pressure overload resulted in a 120% increase in RV pressure (<i>p</i> = 0.0312). The stroke volume index and cardiac index significantly declined (<i>p</i> = 0.0312), and there was a significant decrease in ScvO₂ (<i>p</i> = 0.0312). Both TAP and leaflet perforation achieved moderate-to-severe pulmonary regurgitation. Both procedures led to an incremental trend in RV pressures and resulted in a 24% increase in the stroke volume index. All techniques demonstrated safety and feasibility, with low mortality. This comprehensive model could be reproducible in other large animal models, offering a robust platform for preclinical research into CHD-RV failure models.