Patients born with a univentricular heart require surgical interventions known as the Fontan Palliation Sequence to avoid cyanosis and ultimately death. Using the functional ventricle, venous blood from the inferior vena cava (IVC) and superior vena cava (SVC) is redirected to the pulmonary artery. If performed at an early age, the Fontan Palliation Sequence can greatly improve the quality of life for univentricular patients. Two causes of univentricular hearts are hypoplastic left heart syndrome (HLHS) and hypoplastic right heart syndrome (HRHS). Little is known regarding which functioning ventricle morphology, right or left, provides better life outcomes post-Fontan surgery or the mechanisms that cause the differences in complications and mortality.
A retrospective analysis was conducted on adult Fontan patients within the Ahmanson/UCLA Adult Congenital Heart Disease Center. To be considered eligible for the study, patients from the adult Fontan population had to have an interpretable 12 lead electrocardiogram (ECG) on file (n=238). Eligible patients were then categorized into two groups: left ventricular morphology and right ventricular morphology. Patients who had unclear ventricular dominance were excluded from this analysis.
Out of the total Fontan population (n=238), only patients who had interpretable ECG’s were included (n=167). The patient population was then categorized into groups who had left ventricular morphology (n=119) and right ventricular morphology (n=48). Several health outcomes were measured and compared based on ventricular morphology/dominance. These include use of beta blockers (45% left ventricle dominance v. 27% right ventricle dominance); permanent pacemakers (49% left ventricle dominance v. 35% right ventricle dominance); ablations (25% left ventricle dominance v. 31% right ventricle dominance); the occurrence of at least one cardioversion (36% left ventricle dominance v. 29% right ventricle dominance); unplanned hospitalization (27% left ventricle dominance v. 19% right ventricle dominance); Fontan failure (14% left ventricle dominance v. 21% right ventricle dominance); and death (16% left ventricle dominance v. 6% right ventricle dominance).