Cardiac pathology in nonsurviving infants treated with extracorporeal membrane oxygenation

Extracorporeal membrane oxygénation (ECMO) is now considered standard treatment for respiratory failure refractory to conventional treatment in neonates and older infants. To date, no published series exists regarding cardiac injury in this population of patients. The objective was to characterize cardiac lesions and clinical features in all nonsurviving infants who had ECMO therapy at our institution from 1987 to 1996 and determine whether clinical features predict the nature, severity, or frequency of cardiac damage. We retrospectively reviewed and graded the gross and microscopic pathology of hearts and clinical features of ECMO nonsurvivors (n=20) and compared findings with an age-matched control group (n=8) of non-ECMO nonsurviving infants. The nature and frequency of cardiac lesions were as follows: Right atrial (RA) hemorrhage (17/20), sinoatrial (SA) and atrioventricular (AV) node hemorrhage (12/20), RA necrosis (11/20), endomyocardial hemorrhage in the left ventricle (LV) (9/20), RV hemorrhage (7/20), SA or AV node necrosis (7/20), endomyocardial necrosis of the LV and RV (6/20 and 4/20, respectively), perforation of the free wall of the RA (2/20), organizing thrombus in the RA (1/20). One heart was normal. All controls were normal. Moderate to severe lesions occurred in all symptomatic patients; however, some nonsymptomatic patients had lesions of similar severity. Smaller hearts (<30 g) had more RA necrosis. ECMO therapy is associated with significant cardiac pathology, particularly in the RA. Clinical parameters do not predict which infants sustained moderate to severe cardiac damage.