Ebstein's anomaly: a potential cause of misinterpretation of myocardial perfusion scintigraphy.

We present the case of a 43-year-old woman with a history of Ebstein's anomaly, who was referred for a myocardial perfusion single-photon emission computed tomography (SPECT) study due to angina-like symptoms. Dilatation of the right ventricle and right atrium, apical displacement of the septal tricuspid leaflet, small left ventricle with good left ventricular and a moderate degree of tricuspid regurgitation with mild pulmonary hypertension were found on echocardiography. Myocardial SPECT perfusion imaging with [99m Tc]tetrofosmin demonstrated a large defect in the inferior septal wall in the stress study with mild partial reversibility at rest. Coronary angiography revealed normal coronary arteries. Histological studies have shown that these patients develop increased fibrosis in the left ventricular wall and ventricular septum, especially in the basal and middle region of the septum, which adjoins with the atrialized component of the right ventricle. This is in concordance with the findings of the myocardial perfusion scan in the case described.