Doppler echocardiographic evaluation of cardiac performance in infants on prolonged extracorporeal membrane oxygenation

Abstract

Cardiac performance was evaluated by Doppler echocardiography in 19 infants with persistent pulmonary hypertension before, during and after prolonged extracorporeal membrane oxygenation (ECMO). Systemic arterial pressure was normal before ECMO (67 ± 12 mm Hg), increased during ECMO (78 ± 13 mm Hg) and decreased to baseline after ECMO (p ≤ 0.01). Heart rate was normal before ECMO and did not change during or after ECMO. The left ventricular shortening fraction was normal before ECMO (37 ± 11%), decreased after beginning ECMO (25 ± 11%) and returned to baseline 72 hours after beginning ECMO (p ≤ 0.01). Pulmonary arterial and aortic blood flow velocities were normal before ECMO, decreased 30 to 50% during ECMO and increased to baseline 72 hours after beginning ECMO (p ≤ 0.01). Stroke volume had an identical trend (p ≤ 0.01). Left ventricular velocity of circumferential shortening—an index of contractility—decreased after beginning ECMO (p ≤ 0.05). Left ventricular systolic wall stress—an index of systemic afterload—increased after beginning ECMO (p ≤ 0.01). A patent ductus arteriosus was present in 13 of 19 infants before ECMO, 16 of 19 infants during ECMO and in none of 19 infants after ECMO. Pulmonary arterial systolic pressure was high before ECMO (72 ± 25 mm Hg), began to decrease after 48 hours on ECMO (59 ± 24 mm Hg) and was normal after ECMO (38 ± 18 mm Hg), p ≤ 0.05. It is concluded that ECMO has significant effects on cardiac performance in infants with persistent pulmonary hypertension.