Preferential cephalic redistribution of left ventricular cardiac output during therapeutic hypothermia for perinatal hypoxic-ischemic encephalopathy

Objective: To determine the relationship between left ventricular cardiac output (LVCO), superior vena cava (SVC) flow, and brain injury during whole-body therapeutic hypothermia. Study design: Sixteen newborns with moderate or severe hypoxic-ischemic encephalopathy were studied using echocardiography during and immediately after therapeutic hypothermia. Measures were also compared with 12 healthy newborns of similar postnatal age. Newborns undergoing therapeutic hypothermia also had a cerebral magnetic resonance imaging as part of routine clinical care on postnatal day 3–4. Results: LVCO was markedly reduced (mean+/−SD: 126+/−38 mL/kg/min) during therapeutic hypothermia, whereas SVC flow was maintained within expected normal values (88+/− 27 mL/kg/ min) such that it represented 70% of the LVCO. The reduction in LVCO during therapeutic hypothermia was mainly accounted by a reduction in heart rate (99 +/− 13 BPM versus 123 +/− 17 BPM; p