Cardiac resynchronization therapy improves the ventricular function of patients with Fontan physiology

Past studies have not detected consistent improvement in ventricular function (VFxn) following initiation of cardiac resynchronization therapy (CRT) in Fontan patients. However, these studies used qualitative assessments of VFxn and/or quantitative assessments of VFxn that rely upon anatomic and/or geometric assumptions that may not be valid in patients with single ventricles. To address this, we used quantitative indices of global VFxn (dP/dtic and the Tei index) that are not encumbered by the limitations associated with the indices used in previous studies of CRT in Fontan patients.