Clinical symptoms of right ventricular failure in experimental chronic pressure load are associated with progressive diastolic dysfunction

Right ventricular failure (RVF) due to pressure load is a major cause of death in congenital heart diseases and pulmonary hypertension. The mechanisms of RVF are yet unknown. Research is hampered by the lack of a good RVF model. Our aim was to study the pathophysiology of RVF in a rat model of chronic pressure load. Wistar rats (n=19) were subjected to pulmonary artery banding (PAB, 1.1mm) or sham surgery (CON). All PAB rats developed RVF (reduced cardiac output, RV stroke volume, TAPSE, increased end diastolic pressure, all p<0.05 vs. CON) but clinical symptoms of RVF (inactivity, ruffled fur, dyspnea, ascites) necessitating termination ensued in a subset (5/12) of rats (RVF+) after a period of 52±5 days. Rats with RVF+ had significantly worse RV function and pericardial effusion and liver congestion compared to RVF rats without symptoms (all p<0.05), despite similar pressure load (p=NS RVF vs. RVF+). Chronic pulmonary artery banding invariably leads to RV failure in rats, and a subset transitions to advanced clinical RVF. RVF is characterized by enhanced contractility, progressive diastolic dysfunction and derangement of energy metabolism, thus improving diastolic function and targeting RV metabolism may be the keys to treating RVF. Total RNA optainded ( Heart) of 7 Controls ,5 RVF+ and 4 RVF samples where used for this array study