Abnormal myocardial uptake and clearance of 123I-labeled metaiodobenzylguanidine in patients with chronic renal failure and autonomic dysfunction.

BACKGROUND

Patients with chronic renal failure were evaluated with 123I-labeled metaiodobenzylguanidine (MIBG) myocardial scintigraphy to investigate the relationship between abnormal findings on MIBG scintigrams and autonomic dysfunction.

METHODS AND RESULTS

Eleven control subjects and 20 patients with chronic renal failure (CRF) (serum creatinine level > 8 mg/dl) were evaluated by MIBG myocardial scintigraphy and power spectral analysis (PSA) of the R-R fluctuations of the electrocardiogram. Subjects with CRF were divided into two groups: without (CRF1; nine patients) or with (CRF2; 11 patients) autonomic neuropathy. From 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 clearance rate in the CRF2 group. PSA showed an abnormally low percent low-frequency power and high-frequency power in the CRF2 group. In addition, there was a weak but significant inverse correlation between percent low-frequency power and defect score.

CONCLUSION

Alterations in MIBG scintigrams are seen in patients with autonomic dysfunction in CRF and may be useful for evaluating cardiac sympathetic dysfunction in those patients.