Effect of General Anesthesia on Cardiac Magnetic Resonance Derived Cardiac Function in Tetralogy of Fallot.

Introduction: Surgical palliation of tetralogy of Fallot (TOF) results in excellent short-term survival, however, residual defects result in increased long-term mortality. Depressed right ventricular (RV) and left ventricular (LV) ejection fractions (EF) are associated with adverse outcomes. While cardiac magnetic resonance (CMR) imaging is the preferred modality to assess these patients, some require sedation for successful data acquisition. General anesthesia (GA) has been shown to depress EF and heart rate (HR) in animal models. The effect in patients with congenital heart disease has not been well described. Case Information: A retrospective review was conducted of all CMR patients referred with TOF between January 2011, and May 2017. Patients with significant aortic or mitral valve disease, history of cardiomyopathy, undergoing conscious sedation, or receiving inotropic support were excluded. The cohort was separated into GA and non-sedated groups. A standard anesthetic regimen using sevoflurane was used in all patients. Propensity score matching (PSM) was utilized to adjust for selection bias. The matching algorithm was used in matched subjects to calculate the mean differences in LVEF, RVEF, HR, and cardiac index (CI). A total of 114 patients met criteria, 31 patients were administered GA (mean age 15 years, range 2 – 45, 48% male), while 83 patients received no sedation (mean age 19 years, range 11 – 53, 53% male). The unmatched analysis showed significant depression in LVEF (49.9 vs 56.8%, p Conclusions: GA with sevoflurane results in myocardial depression and significantly depressed CMR derived LVEF, RVEF, and CI. It may be inappropriate to use this data to determine surgical timing for pulmonary valve replacement. Studies examining the effect of GA and the use of alternative protocols should be conducted.