Objective Patients with unoperated single ventricle (SV) rarely survive into adulthood with good functional status and may develop Eisenmenger's syndrome (ES). We report outcomes of a 30-year cohort of such patients.

Methods Adult patients with unoperated SV were identified by searching the Mayo Clinic medical record from 1984 to 2014. Clinical data were collected and compared between patients with pulmonary stenosis (PS) and ES.

Results 24 patients were identified (median peak-age 56 (31–77) years (11 ES, 13 PS); 22 had left ventricular morphology. 50-year transplant-free survival was 65% (95% CI 43 to 81). Median age at death was 55 years (31–77 years); 15 deaths (62%) occurred before oral pulmonary vasodilators were commercially available. Two-thirds of the cohort demonstrated preserved New York Heart Association functional class and median EF was 60% (49% to 62%). The majority of patients to survive into the fifth decade exhibited anatomy of double-inlet LV (DILV) with PS.

Conclusion Selected patients with unoperated SV with PS and ES can survive with good functional class up to the eighth decade with good medical management. DILV/PS appears to be the ideal phenotype for advanced survival. Our outcomes may be considered when such patients with SV having ‘balanced’ physiology are evaluated for Fontan palliation. However, additional prospective study will be necessary to verify this assertion.