Cardiac performance and left ventricular dimensions in neonates with left-sided congenital diaphragmatic hernia before and after surgical repair

BACKGROUND: Congenital Diaphragmatic Hernia (CDH) is associated with significant cardiopulmonary morbidity. Pulmonary Hypertension (PH) and left ventricular (LV) dysfunction are major determinants of outcome. While the impact of CDH repair on pulmonary hemodynamics is recognized, comprehensive serial assessment of cardiac performance, specifically LV dimensions and function, surrounding surgical repair is limited. OBJECTIVES: To characterize changes in LV dimensions, systolic/diastolic function, and global cardiac performance in neonates with CDH immediately before and within 48-72 h after surgical repair. METHODS: A prospective observational cohort study conducted between January 2022 and January 2025 in our tertiary center. Term neonates with isolated, left-sided Bochdalek CDH requiring surgical repair were included. Comprehensive transthoracic echocardiography (TTE) was performed at three time points: (1) Pre-Operative (Pre-Op): Within 24 h before repair (after initial stabilization), (2) Early Post-Operative (E-Post-Op): 48-72 h after completion of surgical repair. (3) One-month Post-Operative (M-Post-Op): One month after completion of surgical repair. Parameters measured from the LV and from the right ventricle (RV), Ventilator settings, inotrope score, and vasoactive-inotrope score (VIS) were recorded concurrently. Data were recorded and analyzed. RESULTS: Thirty neonates met the inclusion criteria (Median gestational age: 38 weeks [IQR 37-39], Birth weight: 3.0kg [IQR 2.7-3.3]). Significant PH was present pre-operatively in 70% (n = 21). Parameters of LV dimensions and function revealed: Left ventricular end-diastolic dimension (LVEDD) and left ventricular end-systolic dimension (LVESD) (absolute and z-score) increased significantly early and one-month post-repair (p < 0.05*). Left ventricular fractional shortening (LVFS), left ventricular ejection fraction (LVEF), and left ventricular global longitudinal strain (LVGLS) decreased significantly in the early post-operative period, then increased again to their normal levels one-month post-repair (p < 0.05*). The decrease in LV systolic function correlated with higher peak Post-Op VIS (r = -0.45, p = 0.01). Improvement in LVEDD correlated with lower oxygen requirements at 7 days post-op (r = -0.38, p = 0.03). The mitral inflow E/A ratio decreased significantly early post-repair and then improved for one month (p = 0.004*), while the average E/e' ratio did not change significantly. Parameters reflecting RV systolic function improved immediately post-repair: Tricuspid annular plane systolic excursion (TAPSE) and Right Ventricular global longitudinal strain (RVGLS) increased significantly (p < 0.05*). Estimated systolic pulmonary artery pressure (ESPAP) decreased significantly (p = 0.002*) and ventricular septal flattening was significantly less common post-repair. CONCLUSIONS: Surgical repair of CDH induces significant acute changes in cardiac performance. While reduction of herniated viscera rapidly improves LV dimensions (indicating relief of compression) and RV function/PAP, it is also associated with a transient impairment in LV systolic function and altered diastolic relaxation pattern in the immediate post-operative period.