[Right ventricular dysplasia and dilated cardiomyopathy observed by radionuclide images]

Four cases of right ventricular dysplasia (RVD) and 28 cases of dilated cardiomyopathy (DCM) were studied. RVD was characterized clinically by syncope, sustained recurrent ventricular tachycardia with left bundle branch block patterns on the surface electrocardiogram, and right heart failure. Furthermore, moderate to severe dilatation of the right ventricle and depressed right ventricular function were apparent on radionuclide angiography. However, left ventricular dilatation and depressed left ventricular function were documented in DCM. Right ventricular volume was proportional to left ventricular volume in DCM, however, right ventricular volume was disproportionately greater in RVD. On the T1-201 perfusion image, left ventricular perfusion defects were delineated in 10 of 26 patients with DCM, and in one of four RVD patients. During two to eight year follow-up periods, six patients died suddenly five of whom had left ventricular perfusion defects. However, in 19 patients without left ventricular perfusion defects, only one sudden death was observed. A connecting link between sudden death and left ventricular perfusion defect is suggested.