Myocardial imaging with I-123-metaiodobenzylguanidine in essential hypertension and renovascular hypertension

Iodine-123 metaiodobenzylguanidine (MIBG) myocardial imaging is considered to reflect cardiac sympathetic function. We performed myocardial MIBG scint igraphy and echocardiography in 27 patients with essential hypertension (EH T), 7 patients with renovascular hypertension (RVHT). and 8 normotensive su bjects (NT) to investigate alterations in MIBG myocardial imaging in the pr esence of hypertension and left ventricular hypertrophy (LVH). EHT were div ided into two groups based on LV wall thickness: EHT with LVH group (greate r than or equal to 13 mm, n=15) and EHT without LVH group (< 13 mm, n=12). The delayed uptake of MIBG was decreased, and the washout rate of MIBG was greater in the EHT with LVH group than EHT without LVH group or NT group. T he washout rate was correlated with LV mass and LV diastolic function (as a ssessed by mitral flow). In RVHT group, the MIBG washout rate increased eve n without LVH, compared with NT and EHT without LVH groups. In summary, the washout rate of MIBG increased in parallel with the development of LVH in EHT and increased independently of the LV mass in RVHT. Cardiac sympathetic function could be altered in hypertensive LVH and in renovascular hyperten sion.