Cardiac Autonomic Dysfunction in Brugada Syndrome

Abstract

Background-Patients with Brugada syndrome present with characteristic ECG abnormalities (atypical right bundlebranch block and ST-segment elevation) and life-threatening ventricular tachyarrhythmias despite structurally normal hearts. Involvement of the autonomic nervous system is suggested by the occurrence of ventricular tachyarrhythmias and sudden death at rest or during sleep and by changes of typical ECG signs under pharmacological modulation of the myocardial autonomic tone. Methods and Results-This study investigated the presynaptic cardiac neuronal reuptake of norepinephrine (uptake 1) in 17 patients with Brugada syndrome and 10 age-matched control subjects with the use of the norepinephrine analogue

The genetic basis of Brugada syndrome: A mutation update

“…The ECG characteristics exhibit day-to-day variation and may not always be present [Veltmann et al, 2006]. However, they may be unmasked by administration of sodium channel blockers, for example, ajmaline or flecainide [Brugada et al, 2000a,b;Shimizu et al, 2000], fever Dumaine et al, 1999], vagotonic agents [Mizumaki et al, 2004;Wichter et al, 2002], a-adrenergic agonists [Pastor et al, 2001], b-adrenergic blockers [Miyazaki et al, 1996], cyclic antidepressants [Goldgran-Toledano et al, 2002], hyper-and hypokalemia [Araki et al, 2003;Littmann et al, 2007a], hypercalcemia [Littmann et al, 2007b], alcohol [Pilz and Luft, 2003], and cocaine [Ortega-Carnicer et al, 2001]. The current diagnostic criteria for BrS are given in Box 1.…”

Novel SCN5A mutation (Q55X) associated with age-dependent expression of Brugada syndrome presenting as neurally mediated syncope

“…Therefore, the proband suffered from two apparently distinct conditions: NMS and Brugada syndrome. The autonomic nervous system has been implicated in both diseases 12,13 , and several case reports have described patients exhibiting clinical phenotypes of both NMS and Brugada syndrome [3][4][5] .…”

Cardiac autonomic imaging with SPECT tracers

“…34 Shortly thereafter, efforts at Michigan shifted toward positron emission tomography (PET) compounds, resulting in clinical mIBG studies thereafter being performed mostly in Europe and Japan. While early in development, mIBG was labeled with 131 I, high energy emissions (365 keV), including b -particles, and the 8-day half-life led to use of 123 I that emits predominantly 159-keV gamma photons, with a half-life of 13.2 h, thus well-tolerated and easily imaged with single-photon emission computed tomography (SPECT). Unlike NE, after uptake in the pre-synaptic terminal via the NET-1 pathway, 123 I-mIBG is not catabolized, and thereby localizes to a high cytoplasmic concentration.…”

“…Gill et al 129 found asymmetrical uptake of 123 ImIBG (less in septum) in 47% of patients with VT and ''clinically normal'' hearts, particularly obvious in patients with exercise-induced VT. Interestingly, PET autonomic tracer (i.e., 11 C-HED) imaging of particular primary arrhythmias, such as right ventricular outflow tract tachycardia 130 and Brugada syndrome, shows focal defects in specific myocardial walls. 131 Regional autonomic abnormalities can also be seen in nonischemic cardiomyopathies, such as Chagas disease in which the posterolateral, inferior, and apical walls are selectively affected. In one study of 26 patients with chronic Chagas cardiomyopathy, 123 I-mIBG defects correlated with the occurrence of sustained VT. 132 Further investigation of such observations may lead to better understanding of the pathophysiology of cardiac autonomic innervation, as well as the particular disease entities.…”