A case of congenital left ventricular diverticulum with pulmonary stenosis and its scintigraphic characteristics.

We encountered a 31-year-old female patient with mild valvular pulmonary stenosis who had no abnormality in the electrocardiogram but pulmonary dilatation in the chest radiograph. Two-dimensional echocardiography and magnetic resonance imaging demonstrated two small protrusions at the interventricular septum indicating diverticula. Large perfusion defects were observed at the anterior wall in the thallium-201 myocardial tomograms. Short axial and vertical long axial images by ECG-gated blood pool tomography revealed an out-pouching best seen during diastole and a good contraction during systole in the corresponding areas. These findings suggested the presence of thin but normal myocardium in the anterior wall, i.e. a muscular type of left ventricular diverticulum. The presence of the muscular type of left ventricular diverticulum at the anterior and septal walls was confirmed by contrast left ventriculography. A congenital diverticulum at the anterior and septal walls with pulmonary stenosis is very rare. Furthermore, its scintigraphic images were quite characteristic and useful for its diagnosis.