058 - Ratio of Right Ventricle to Left Ventricle Dimensions: A simple Echocardiographic Prognostic Marker for Congenital Diaphragmatic Hernia

Publication Number: 58.6490

Sanjeev Aggarwal, Children's Hospital of Michigan, Detroit, MI, United States; Manar Nakdali, Children's Hospital of Michigan, Macomb, MI, United States; Girija Natarajan, Central Michigan University College of Medicine, Detroit, MI, United States

Background: Despite improved survival in recent years, congenital diaphragmatic hernia (CDH) remains associated with mortality and neonatal morbidity. Pulmonary hypertension (PH) and ventricular hypoplasia and dysfunction, along with lung hypoplasia, comprise the underlying pathophysiology. The ratio of right ventricular (RV) to LV diameter assesses both septal shift due to PH and RV dilation as well as intrinsic reduced LV size and has been shown to correlate with PH severity in older children.

Objective: To compare ratios of RV:LV dimensions in normal controls and neonates with CDH and to evaluate their association with outcomes in neonates with CDH.

Design/Methods: In this single center retrospective study, early ( < 48 hours age) ECHOs of neonates (≥34 weeks gestation) with CDH (n = 58) and term controls (n=41) were reviewed by a single reader blinded to clinical outcomes. RV:LV diameter ratios in end diastole and end systole were obtained offline from the parasternal short-axis view at the level of the papillary muscles with the RV free wall in view and were measured from one endocardial surface to the other. In addition, we measured RV and LV areas on the 4-chamber view and minute distance, the product of velocity time integral (VTI) and heart rate (HR), a surrogate marker for cardiac output for both ventricles. Statistical analyses included t-test and chi-square test, and significance was taken as p< 0.05.

Results: Our cohort (n=58) comprised 34 (59%) males and predominantly (81%) left sided CDH; 34 (58.6%) infants died or received ECMO and 24 (41.4%) survived without ECMO. Controls included 22 (53.7%) males. RV:LV ratios for diameters and areas in systole and diastole were significantly higher for CDH infants, compared to controls [Table1]. LV and RV VTI-HR products were significantly higher in controls, but the ratio was not different, compared with infants with CDH. Among subgroups of infants with CDH who died or underwent ECMO vs survivors without ECMO, RV:LV ratios for diameters in systole and diastole were significantly higher in the death/ECMO group. The death/ECMO group had more biventricular dysfunction, evidenced by lower fractional area change. None of the other measures showed significant differences.

Conclusion(s): The RV: LV diameter ratio on an early echocardiogram is significantly increased in infants with CDH, compared to controls and in the subgroup that died or underwent ECMO. Further validation of the prognostic utility of this measure in multisite larger cohorts is warranted.

Table 1: Comparison of ECHO data of infants with CDH (n=58) and normal controls (N=41)


Table 2: Comparison of ECHO data of infants with CDH who died or underwent ECMO (n=34) and survivors without ECMO (n=24)