PNNL

Abstract

Right ventricular (RV) function is important for patients supported by veno-arterial extracorporeal membrane oxygenation (VA-ECMO), especially for patients with pulmonary hypertension, same as left ventricular (LV) function. This study was designed to evaluate the difference between RV and LV metabolic change by short-term VA-ECMO in vivo immature swine heart. Mixed breed male Yorkshire pigs (33-49 days old) were exposed under loaded ventricular condition without ECMO support (Ctrl, n=5) or unloaded by VA-ECMO (ECMO, n=10) to identify difference of both ventricular metabolic change. VA-ECMO carried out for 8 hours at 80-100 ml/kg/min flow rate. Half cases of pigs with ECMO received intravenous thyroid hormone (T3) continuously (ECMO-TH).The Carbon 13 (13C)-labeled substrates ([2-13C]lactate, [2,4,6,8-13C]octanoate and [U-13C]long-chain mixed fatty acids as metabolic tracers were systemically infused for the final 60 minutes before tissue extraction. Metabolic analyses by nuclear magnetic resonance showed that both RV and LV have similar trend on contributions of 13C- labeled substrates to the citric acid cycle in Ctrl group. VA-ECMO produced higher long-chain mixed fatty acids and lower lactate contribution to the citric acid cycle via inhibition of pyruvate dehydrogenase, and T3 supplementation promoted lactate metabolism in both ventricles. However these metabolic shifts were small in RV compared with LV. Metabolic manipulation with loading change by VA-ECMO and T3 supplementation had varying degrees of impacts on RV and LV. This finding suggests that VA-ECMO support for RV failure patients requires a more aggressive metabolic control than the patients with only LV failure.