Right Ventricular Electrophysiology and Arrhythmias in Adults With Congenital Heart Disease: Scientific Basis for Management.

Right ventricular (RV) dysfunction and arrhythmias are major concerns in adults with congenital heart disease (CHD). The relationship between RV dysfunction and arrhythmogenesis is bidirectional, with structural and electrical remodeling contributing to arrhythmia development and, conversely, arrhythmias exacerbating RV failure. In addition to an RV in the standard subpulmonary position failing because of pressure and/or volume overload, other phenotypes associated with RV dysfunction in CHD include transposition of the great arteries with a systemic (subaortic) RV and univentricular hearts with a predominant RV morphology. The RV is better suited for low-pressure workloads. When it supports the systemic circulation, the RV undergoes remodeling changes that promote arrhythmias, which can provoke a cycle of worsening dysfunction and arrhythmogenesis. Arrhythmias can worsen RV dysfunction by impairing hemodynamic stability, reducing cardiac output, provoking dyssynchrony, and inducing tachycardia-induced cardiomyopathy. Cellular mechanisms, including myocardial fibrosis, dysregulation of ion channels, and abnormal gap junction function, are central to this process, facilitating both re-entrant and triggered arrhythmias. Conduction disturbances, whether inherent or caused by fibrosis or pacing, compound these effects, aggravating both RV dysfunction and arrhythmia perpetuation. Management strategies must be comprehensive and include pre-emptive approaches to minimize arrhythmias, alongside early detection. Individualized therapies may include catheter ablation and cardiac implantable electronic devices, with treatment tailored to the specific RV phenotype and arrhythmia type. In this review we emphasize the importance of personalized interventions to prevent the vicious cycle of RV dysfunction and arrhythmias in CHD. Further research is essential to optimize therapeutic strategies and address care-limiting knowledge gaps.