Congenital heart disease and arrhythmia disorders in newborns with congenital diaphragmatic hernia: a 23-year experience at a UK university pediatric surgical centre.

Purpose: Congenital diaphragmatic hernia (CDH) is associated with congenital heart disease (CHD) and index newborns reportedly may experience cardiac arrhythmia disorders [Tella et al.-Pediatric Critical Care Medicine 2022]. This study analyses, details and reports contemporary outcome metrics of CHD and cardiac rhythm disease (CRD) in CDH babies attending a university surgical centre.

Methods: Retrospective analysis of medical records of all newborns undergoing Bochdalek CDH repair between 1999 and 2021 at a university paediatric surgical centre. CDH newborns with CHD and neonatal arrythmias were identified from echocardiogram and electrocardiogram (ECG) investigative studies. Operative native diaphragm and / or use of patch repair(s) was documented. Outcome(s) measured-(i) mortality and (ii) cardiopulmonary interventions including ventilatory strategies-ECMO (%), inotropes and anti-arrhythmic therapy(s).

Results: Of 173 CDH neonates, 95 (55%) had CHD of which 9 babies (10%) had cardiac arrhythmias. CDH and co-existing CHD was linked with (a) lower infant birth weights (3130 g vs 3357 g, p = 0.05), (b) increased use of inotrope agents (48.4% vs 39.3%, p = 0.03) and (c) greater use of high-frequency oscillatory ventilation (38.9% vs 23%, p = 0.004). CDH babies experiencing arrythmias were at higher risk (%) of developing pulmonary hypertension (66.7% vs 28.7%, p = 0.01). No significant differences were observed in ECMO utilisation (12% vs 6%, p = 0.46) or patch repair(s) (53% vs 46%, p = 0.06) in CDH patients with and without CHD. CHD was not associated with increased risk(s) of mortality (OR 2.58, 95% CI 0.81-8.24, p = 0.11). Of 9 index CDH patients with arrhythmias-4 babies (44%) required interventional treatments.

Conclusion: CHD was prevalent in a high percentage (%) of CDH newborns treated at this university centre and associated with increased use (%) of cardiovascular respiratory support including patch repair. A minority of patients (2.3%) had cardiac rhythm disorders requiring treatment(s). In those developing arrhythmias pulmonary hypertension may be a risk-linked event. Optimising outcomes to offset pulmonary hypertension requires further appraisal. Future large-scale population studies may help underscore the 'real apparent incidence' of cardiac rhythm disorders in CDH.