%0 Journal Article
%T 123I-MIBG Scintigraphy as a Powerful Tool to Plan an Implantable Cardioverter Defibrillator and to Assess Cardiac Resynchronization Therapy in Heart Failure Patients
%A Antonella Stefanelli
%A Giorgio Treglia
%A Alessandro Giordano
%J International Journal of Molecular Imaging
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/690468
%X Iodine-123-metaiodobenzylguanidine (123I-MIBG) scintigraphy is a nuclear medicine technique which describes the functional status of the cardiac sympathetic nervous system. It is well known that an autonomic dysfunction is present in heart failure setting as a neuronal uptake of norepinephrine is impaired in the failing myocardium. Reduction in sympathetic nervous function in the heart, measured by reduced myocardial uptake of 123I-MIBG, is an indicator of poor prognosis for heart failure patients. The aim of this paper was to investigate the role of 123I-MIBG scintigraphy in evaluating the need of implantable cardioverter defibrillator (ICD) and the response to cardiac resynchronization therapy (CRT) in heart failure patients. For this purpose scientific literature data on these topics were reviewed. Based on literature data, 123I-MIBG scintigraphy seems to be a useful tool to assess which patients may benefit most from an ICD implantation to reduce the risk of ventricular arrhythmia or sudden cardiac death. Furthermore, 123I-MIBG scintigraphy seems to predict which patients will response to CRT with an improvement in left ventricular function. 1. Introduction Heart failure (HF) is characterized by alterations in myocardial sympathetic nerve activity; an increased sympathetic response is initially favorable by serving as compensation for decreased cardiac output, but as HF progresses, this response leads to deleterious neurohormonal and myocardial structural changes that worsen the condition and increase the likelihood of arrhythmias and cardiac death [1]. Myocardial innervation imaging with iodine 123 metaiodobenzylguanidine (123I-MIBG) scintigraphy provides a noninvasive tool for the investigation of cardiac sympathetic innervation; this technique can also demonstrate drug-induced changes in cardiac adrenergic activity [2]. Radiolabeled MIBG is considered an established sympathetic neuron-imaging agent useful to study the organs richly innervated by the sympathetic nervous system. MIBG is an analog of guanethidine and is taken up by the postganglionic presynaptic nerve endings of the adrenergic nervous system [3¨C6]. After depolarization, MIBG is released into the synaptic cleft like norepinephrine but is not metabolized. Labeling MIBG with 123I allows the visualization of adrenergic innervation in vivo; 123I-MIBG scintigraphy not only displays the presence of noradrenergic innervation but also its functional capability [3¨C6]. About the scintigraphic procedure, planar images of the thorax are acquired 15 minutes (early image) and 4 hours (delayed
%U http://www.hindawi.com/journals/ijmi/2012/690468/