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Doppler echocardiographic evaluation of cardiac performance in infants on prolonged extracorporeal membrane
1Department of Cardiology, Children's Hospital National Medical Center, Washington, DC 20010.
Insights
Extracorporeal membrane oxygenation (ECMO) temporarily impacts infant cardiac function, decreasing contractility and increasing afterload. However, cardiac performance recovers to baseline levels after ECMO treatment for persistent pulmonary hypertension.
Area of Science:
- Pediatric Cardiology
- Neonatology
- Cardiovascular Physiology
Background:
- Persistent pulmonary hypertension of the newborn (PPHN) is a critical condition requiring advanced support.
- Extracorporeal membrane oxygenation (ECMO) is a life-saving therapy for neonates with PPHN unresponsive to conventional treatment.
- Understanding the hemodynamic effects of ECMO on infant cardiac function is crucial for optimizing patient management.
Purpose of the Study:
- To evaluate the impact of prolonged extracorporeal membrane oxygenation (ECMO) on cardiac performance in infants with persistent pulmonary hypertension.
- To assess changes in systemic arterial pressure, heart rate, ventricular function, and blood flow velocities during and after ECMO therapy.
Main Methods:
- Doppler echocardiography was used to assess cardiac function in 19 infants with PPHN before, during, and after ECMO.
- Key hemodynamic parameters including systemic arterial pressure, heart rate, left ventricular shortening fraction, and blood flow velocities were measured.
- Indices of contractility (velocity of circumferential shortening) and systemic afterload (systolic wall stress) were analyzed.
Main Results:
- ECMO increased systemic arterial pressure and left ventricular systolic wall stress, indicating increased afterload.
- Left ventricular shortening fraction and velocity of circumferential shortening decreased during ECMO, suggesting reduced contractility.
- Pulmonary arterial systolic pressure decreased over time on ECMO, returning to normal post-therapy.
- Patent ductus arteriosus was common before and during ECMO but resolved after treatment.
Conclusions:
- Prolonged ECMO therapy in infants with PPHN causes significant but reversible alterations in cardiac performance.
- These changes include increased afterload and decreased contractility, which normalize after ECMO cessation.
- Echocardiographic monitoring is essential for managing cardiac function during and after ECMO in this population.
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 less than or equal to 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 less than or equal to 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 less than or equal to 0.01). Stroke volume had an identical trend (p less than or equal to 0.01). Left ventricular velocity of circumferential shortening--an index of contractility--decreased after beginning ECMO (p less than or equal to 0.05). Left ventricular systolic wall stress--an index of systemic afterload--increased after beginning ECMO (p less than or equal to 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 less than or equal to 0.05.(ABSTRACT TRUNCATED AT 250 WORDS)