Disorders of the Autonomic Nervous System in Patients With Brugada Syndrome: A Pilot Study

Autonomic Disorders in Brugada Syndrome. Introduction: The aim of this study was to examine autonomic disorders in patients with Brugada syndrome by performing a cardiac sympathetic innervation evaluation, a head‐up tilt‐test (HUT) and heart rate variability (HRV) analysis. Methods and Results: We enrolled 20 patients with Brugada syndrome (mean age 42.5 ± 8.8 years), 9 with spontaneous and 11 with an induced type 1 electrocardiogram (ECG) in the setting of symptoms and 20 age‐matched controls. All subjects underwent a HUT with parallel measurements of plasma catecholamines and cortisol, a 123I‐metaiodobenzylguanidine single photon emission tomography, and HRV evaluation. Ten control subjects participated in the innervation portion of the study. The tilt‐test with clomipramine challenge was positive in 15 of 20 (75%) patients (7 spontaneous, 8 induced) and in 1 in controls (P < 0.01). A sympathoadrenal imbalance was shown in positive tests. The pattern of innervation in all groups was heterogenic and similar to controls with a trend towards lower measurements in patients with a spontaneous type 1 ECG and a positive HUT. HRV analysis did not reveal any significant differences during day and night. Four patients (20%) had sustained ventricular arrhythmias during a follow‐up of 31.1 ± 8.6 months, but no correlations with innervation or response to tilting were found. Conclusion: A high susceptibility to vasovagal syncope was observed in patients with Brugada syndrome, which could be disease‐related symptoms. Conversely, sympathetic innervation was observed to follow a physiological, heterogenic pattern; however, these factors did not have prognostic value for life‐threatening arrhythmias. (J Cardiovasc Electrophysiol, Vol. pp. 773‐780, July 2010)