ABNORMAL MYOCARDIAL UPTAKE AND CLEARANCE OF I-123 LABELED METAIODOBENZYLGUANIDINE IN PATIENTS WITH CHRONIC-RENAL-FAILURE AND AUTONOMIC DYSFUNCTION

Background. Patients with chronic renal failure were evaluated with I- 123-labeled metaiodobenzylguanidine (MIBG) myocardial scintigraphy to investigate the relationship between abnormal findings on MIBG scintig rams and autonomic dysfunction. Methods and Results. Eleven control su bjects and 20 patients with chronic renal failure (CRF) (serum creatin ine level >8 mg/dl) were evaluated by MIBG myocardial scintigraphy and power spectral analysis (PSA) of the R-R fluctuations of the electroc ardiogram, Subjects with CRF were divided into two groups: without (CR F1; nine patients) or with (CRF2; 11 patients) autonomic neuropathy, F rom MIBG images, the heart/mediastinum mean count rate, defect score, which was scored visually, and clearance rate were calculated, Percent low-frequency power and high-frequency power were obtained from PSA, MIBG scintigrams showed decreased heart/mediastinum mean count rate, a high defect score in both initial and delayed images, and rapid clear ance rate in the CRF2 group, PSA showed an abnormally low percent low- frequency power and high-frequency power in the CRF2 group, In additio n, there was a weak but significant inverse correlation between percen t low-frequency power and defect score. Conclusion, Alterations in MIB G scintigrams are seen in patients with autonomic dysfunction in CRF a nd may be useful for evaluating cardiac sympathetic dysfunction in tho se patients.