Abnormal cardiac sympathetic nerve function in a patient with pheochromocytoma. An analysis using 123I metaiodobenzylguanidine scintigraphy

A 23-year-old woman with pheochromocytoma had a high level of plasma norepinephrine (NE) (6039 pg/ml) and 123I metaiodobenzylguanidine (MIBG) scintigram showed decreased myocardial retention. After surgical resection, plasma norepinephirine was normalized and the myocardial retention of 123I MIBG gradually improved. These findings suggest that the possibility that the excess of circulating norepinephirine caused by pheochromocytoma could damage the cardiac sympathetic nerve function and 123I MIBG scintigraphy is a useful method of evaluating abnormalities.