Cardiac Sympathetic Neuroimaging
DOI link for Cardiac Sympathetic Neuroimaging
Cardiac Sympathetic Neuroimaging book
Symptoms or signs of abnormal autonomic nervous system function occur commonly in many diseases. Clinical evaluations have depended on physiologic, pharmacologic, and neurochemical approaches. Imaging of sympathetic noradrenergic innervation has been introduced and applied especially in the heart. Most studies have used 123I-metaiodobenzylguanidine (123I-MIBG). Parkinson’s disease (PD) with orthostatic hypotension features cardiac sympathetic denervation, whereas multiple system atrophy, often difficult to distinguish clinically from PD, features intact cardiac sympathetic innervation. Decreased cardiac uptake or increased “washout” of 123I-MIBG-derived radioactivity is associated with worse prognosis or more severe disease in a variety of conditions. PD entails a postganglionic sympathetic noradrenergic lesion, implying that the disease is not only a movement disorder, from dopamine loss in the nigrostriatal system of the brain, but also a dysautonomia, from norepinephrine loss in the sympathetic nervous system of the heart. Abnormal time-activity curves for myocardial 123I-MIBG-derived radioactivity may reflect local sympathetic nervous activation.