Disorders of the autonomic nervous system in patients with Brugada syndrome: a pilot study.
BACKGROUND
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.


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 (123)I-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.


CONCLUSIONS
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.
Second Cardiology Department, Onassis Cardiac Surgery Center, Athens, Greece.
Anna
A
Kostopoulou
Maria
M
Koutelou
Georgios
G
Theodorakis
Athanasios
A
Theodorakos
Efthimios
E
Livanis
Themistoklis
T
Maounis
Antigoni
A
Chaidaroglou
Dimitrios
D
Degiannis
Vassilis
V
Voudris
Dimitrios
D
Kremastinos
Dennis
D
Cokkinos
D019797:3-Iodobenzylguanidine; D000328:Adult; D001341:Autonomic Nervous System / Q000378:metabolism / Q000503:physiopathology*; D015415:Biomarkers / Q000097:blood; D053840:Brugada Syndrome / Q000097:blood / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D016022:Case-Control Studies; D002395:Catecholamines / Q000097:blood; D004562:Electrocardiography; D005260:Female; D006115:Greece; D006321:Heart / Q000294:innervation*; D006339:Heart Rate; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011187:Posture; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D018570:Risk Assessment; D019462:Syncope, Vasovagal / Q000209:etiology* / Q000503:physiopathology; D018667:Tilt-Table Test; D015899:Tomography, Emission-Computed, Single-Photon; D055815:Young Adult
D015415:Biomarkers; D002395:Catecholamines; D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine; D006854:Hydrocortisone