In tetralogy of Fallot (TOF), it is now clear that the fate of the myocardium is a major determinant of outcome late after repair.1 With each passing decade of experience since the first successful surgical procedures, we have learned more and more about how the myocardium behaves in response to pressure and volume loading, and we have seen more heart failure–related complications as a result. Even when the septal defect is closed and the pulmonary valve replaced and competent, residual biventricular dysfunction (right and/or left, systolic and/or diastolic) may become more pronounced over time and affect long-term outcome. Cumulative studies now paint a convincing picture of a cause-effect relationship between myocardial dysfunction and death or ventricular arrhythmia.
Broberg CS. Myocardial Dysfunction in Tetralogy of Fallot and Its Association With Outcome. JAMA Cardiol. 2017;2(6):683-684. doi:10.1001/jamacardio.2016.6020