Introduction: We analyzed cardiac position in neonates with CDH before and after diaphragmatic repair on ECMO, and correlated these findings with clinical outcome.

Methods: Echocardiograms (ECHO) were performed on 21 neonates with CDH (5 right, 16 left) and without heart defects prior to ECMO, and were repeated within 5 days after repair on ECMO. A standard transverse subcostal 4-chamber view was used to determine the infant's midline plane, and to measure the angle between this plane and the heart's interventricular septum(cardiac angle). Deviation from normal (45° determined in non-CDH, ECMO treated subjects) was defined as the absolute value of the difference between the measured cardiac angle and 45°. Left ventricular mass (LVM) was also calculated. The Mann-Whitney-Wilcoxon Rank-sum test was used to compare medians of ECHO measured parameters and clinical aspects between survivorsv non-survivors.

Results: Twelve infants (57%) survived, 9 (43%) died. Median time on ECMO was significantly longer for non-survivors (624 hrs) v survivors (244 hrs, p=.0003). There were no differences between groups in birth weight, gestation, or cardiac deviation presurgery (45° non-survivors v 40° survivors). In contrast, cardiac angle deviation after diaphragmatic repair showed greater deviation persisting in non-survivors (27°) v survivors (7°, p=.0025). LVM was significantly less in non-survivors (1.5 v 2.9 g/kg, p=.0028). All infants who died also had persistent pulmonary artery hypertension.

Conclusion: Non-survivors with CDH repair on ECMO demonstrated persistent cardiac malposition even after surgery. This finding may be an early, easily measured and reproducible indicator of poor outcome.