Infective endocarditis in an adult with undiagnosed tetralogy of Fallot: a case report of a rare presentation.

Background: Unrepaired tetralogy of Fallot (TOF) is uncommonly diagnosed in adulthood and only 3% of patients survive to reach the age of 40 without surgical repair. If unrepaired, these patients are at risk for infective endocarditis (IE).

Case presentation: In this report, we present a case of a middle-aged, previously healthy female whose only complaint was unexplained fever. Echocardiography led to the discovery of undiagnosed TOF complicated with IE with a vegetation on the right ventricular (RV) side of the ventricular septal defect (VSD) which was appropriately managed with antibiotics.

Conclusions: In rare cases of acyanotic TOF where there is a lesser degree of right ventricular outflow tract obstruction (RVOTO), patients may survive into adulthood and can be asymptomatic till becoming initially presented with complications such as infective endocarditis.