Early postoperative beta-blockers are associated with improved cardiac output after late complete repair of tetralogy of Fallot: a retrospective cohort study

Tetralogy of Fallot is the most common cyanotic congenital heart disease. For decades, our institution has cared for humanitarian patients with late presentation of tetralogy of Fallot. They are characterized by severe right ventricular hypertrophy with consecutive diastolic dysfunction, increasing the risk of postoperative low cardiac output syndrome (LCOS). By right ventricular restrictive physiology, we hypothesized that patients receiving early postoperative beta-blockers (within 48 h after cardiopulmonary bypass) may have better diastolic function and cardiac output. This is a retrospective cohort study in a single-center tertiary pediatric intensive care unit. We included > 1-year-old humanitarian patients with a confirmed diagnosis of tetralogy of Fallot undergoing a complete surgical repair between 2005 and 2019. We measured demographic data, preoperative echocardiographic and cardiac catheterization measures, postoperative mean heart rate, vasoactive-inotropic scores, LCOS scores, length of stay, and mechanical ventilation duration. One hundred sixty-five patients met the inclusion criteria. Fifty-nine patients (36