Impact of sympathetic innervation on recurrent life-threatening arrhythmias in the follow-up of patients with idiopathic ventricular fibrillation

Abstract

Impairment of sympathetic innervation may indicate a higher risk of future recurrent episodes of life-threatening ventricular tachyarrhythmias in patients with IVF. Studies in larger cohorts are required to validate the significance of (123)I-MIBG SPECT during the long-term follow-up of these patients.

ASNC imaging guidelines for SPECT nuclear cardiology procedures: Stress, protocols, and tracers

“…Cardiac 123 I-mIBG imaging is currently indicated for ''scintigraphic assessment of sympathetic innervation of the myocardium in patients with New York Heart Association [NYHA] class II or class III HF and left ventricular ejection fraction [LVEF] B35% … and to help identify patients with lower oneand two-year mortality risks, as indicated by an [HMR] ratio C1.6.'' Nevertheless, much literature suggests a potential broader use, 91 including identification of patients at increased risk of lethal cardiac arrhythmias in the setting of HF, [92][93][94][95] evaluating primary arrhythmic conditions, [96][97][98][99][100] assessing the presence and risk of ischemic heart disease, 101,102 including in situations of hibernating myocardium 103,104 and post-infarction, [105][106][107] evaluating pre-and post-cardiac transplant patients, [108][109][110] identifying diabetic patients at increased risk from cardiac autonomic dysfunction, 111,112 and monitoring toxicity from chemotherapy. 113 However, based on currently available literature, published guidelines, and the FDA package insert, the following indications can be recommended: 114 • For patients with NYHA class II or III heart failure with LVEF B35% to help stratify risk and to promote more informed clinical decision-making when the result of 123 I-mIBG study is likely to influence the decision regarding ICD implant.…”

How to use myocardial 123I-MIBG scintigraphy in chronic heart failure

“…In the past two decades, a large number of investigators have demonstrated decreased myocardial 123 I-MIBG uptake in patients with chronic heart failure (CHF) and have shown that those with the lowest uptake tend to have the poorest prognosis [2][3][4][5][6][7][8][9][10][11][12]. There have also been findings suggesting that abnormalities of myocardial 123 I-MIBG uptake may be predictive of increased risk of ventricular arrhythmia and sudden cardiac death [13,14]. One factor that has constrained acceptance of cardiac 123 I-MIBG imaging as a clinical management tool in heart failure has been the variability of the technical aspects of the procedure.…”

Ventricular arrhythmias and autonomic nervous system: evolving role of radionuclide imaging

“…Risk stratification of patients beyond left ventricular ejection fraction (LVEF) has been the focus of most studies. [3][4][5][6] They have almost exclusively studied the sympathetic innervation of the ventricular myocardium, which is easier to evaluate, with currently available radionuclide tracers than parasympathetic innervation. The principle question these studies have tried to address is: Does sympathetic denervation as assessed by nuclear imaging help in better risk stratification of heart failure (HF) patients by identifying those at increased risk of ventricular arrhythmia (VA)?…”