Gerbode defect following endocarditis and misinterpreted as severe pulmonary arterial hypertension

A Gerbode -type defect is a ventricular septal defect communicating directly between the left ventricle and right atrium. It is usually congenital, but rarely is acquired, as a complication of endocarditis. This can be anatomically possible because the normal tricuspid valve is more apically displaced than the mitral valve. However, identification of an actual communication is often extremely difficult, so a careful and meticulous echocardiogram should be done in order to prevent echocardiographic misinterpretation of this defect as pulmonary arterial hypertension. The large systolic pressure gradient between the left ventricle and the right atrium would expectedly result in a high velocity systolic Doppler flow signal in right atrium and it can be sometimes mistakably diagnosed as tricuspid regurgitant jet simulating pulmonary arterial hypertension.

We present a rare case of young woman, with endocarditis who presented with severe pulmonary arterial hypertension. The preoperative diagnosis of left ventricle to right atrial communication (acquired Gerbode defect) was suspected initially by echocardiogram and confirmed at the time of the surgery.

A point of interest, apart from the diagnostic problem, was the explanation for its mechanism and presentation. The probability of a bacterial etiology of the defect is high in this case.