Imaging cardiac neuronal function and dysfunction

Abstract

In recent years, the importance of alterations of cardiac autonomic nerve function in the pathophysiology of heart diseases including heart failure, arrhythmia, ische-mic heart disease, and diabetes has been increasingly recognized. Several radiolabeled compounds have been synthesized for noninvasive imaging, including single photon emission CT and positron emission tomography (PET). The catecholamine analogue I-123 metaiodobenzylguanidine (MIBG) is the most commonly used tracer for mapping of myocardial presynaptic sympathetic innervation on a broad clinical basis. In addition, radiolabeled catecholamines and catecholamine analogues are available for PET imaging, which allows absolute quantification and tracer kinetics modeling. Postsynaptic receptor PET imaging added new insights into mechanisms of heart disease. These advanced imaging techniques provide noninvasive, repeatable in vivo information of autonomic nerve function in the human heart and are promising for providing profound insights into molecular pathophysiology, monitoring of treatment, and determination of individual outcome.

Traditional and novel methods to assess and prevent chemotherapy-related cardiac dysfunction noninvasively

“…Novel SPECT techniques for early detection of cardiotoxicity are shown in Table 6. 46 These novel techniques include static volume indices and functional LV indices by gated SPECT ERNA and MPI, 27,28 sympathetic neuronal imaging with a wide variety of SPECT and PET tracers, [47][48][49][50][51][52][53][54][55] In-111 antimyosin which is a specific marker of myocyte injury and necrosis, 54,56,57 Tc-99m annexin V which visualized apoptosis and programmed cell death, [58][59][60] fatty acid scintigraphy which visualizes fatty acid retention in the lipid pool of the cytosol which can be impaired by cardiotoxic agents, 61 and direct imaging of In-111 trastuzumab to study trastuzumab targeting of the myocardium have been considered. 62 Each of these techniques would require a prospective clinical trial to assess its incremental value in avoiding clinical CHF.…”

“…Initial reports have demonstrated MIBG uptake at low dose of doxorubicin prior to and following decline in LV function. 50,51 A significant decrease in myocardial MIBG uptake at high cumulative doses was observed in nearly all patients with a 10% reduction of LVEF. 51,52 These data suggest monitoring drug-induced cardiac sympathetic damage may facilitate recognition of patients at risk of developing CHF who may benefit from early treatment of CHF with or without termination of chemotherapy.…”

Assessment of the 18F-Labeled PET Tracer LMI1195 for Imaging Norepinephrine Handling in Rat Hearts

“…It is well known that chronic hyperactivation of this system in patients with heart failure plays an important role in the vicious cycle of advanced disease progression by increasing myocardial energy requirements, afterload, and arrhythmias (1). Radionuclide imaging techniques provide noninvasive information about cardiac sympathetic innervation and nerve activity (2,3). These techniques uniquely facilitate understanding of the local cardiac sympathetic nervous system in physiologic and pathologic conditions, in contrast to blood tests, which only assess systemic sympathetic conditions.…”

“…Most commonly used for cardiac sympathetic nerve imaging are norepinephrine analog tracers, including 123 I-metaiodobenzylguanidine for SPECT and 11 C-hydroxyephedrine for PET (2)(3)(4)(5). The PET assay is superior to SPECT in terms of quantification and temporal and spatial resolution.…”

Efeito do carvedilol a curto prazo na atividade simpática cardíaca pela cintilografia com 123I-MIBG

“…Recently, the importance of identifying alterations in the autonomic cardiac innervation in cardiovascular diseases, including heart failure (HF), arrhythmias, ischemic heart diseases and diabetes has been increasingly acknowledged [3][4][5] .…”