[Clinical meaning of 123I-MIBG myocardial SPeCT in patients with dilated cardiomyopathy]

MIBG-myocardial SPECT was performed on patients with dilated cardiomyopathy (DCM) undergoing treatment with beta blocker (Nipradilol). The findings of MIBG-myocardial SPECT were compared with the changes in cardiac function obtained by echocardiograms. The patients enrolled in the study were seven males who has been diagnosed as definitely suffering from DCM according to diagnostic guidelines provided by the Ministry of Health and Welfare. The patients were aged 57.5 +/- 10.2 years. Following intravenous administration of 111 MBq (3 mCi) of MIBG, myocardial SPECT was taken 20 minutes, and 4 hours later. The washout rate of the left ventricular wall was higher in the unchanged group (40.7 +/- 1.2%) than in the improved group (30.3 +/- 6.1%). Both the early and delayed images showed higher extent and severity scores for the unchanged group than for the improved group. A correlation of LVEF with the washout rates was demonstrated (r = -0.819, p < 0.05). A correlation was also observed between the variations in LVEF before and after beta blocker therapy with the washout rates (r = -0.969, p < 0.01), MIBG-myocardial SPECT suggested possibility of the evaluation of severity and prognosis in the patients with DCM.