Distribution and Prognostic Significance of Fragmented QRS in Patients With Brugada Syndrome.
BACKGROUND
Fragmented QRS complexes (fQRS) in the right precordial leads are associated with occurrence of ventricular fibrillation (VF) in Brugada syndrome. Recently, epicardial mapping has revealed abnormal electrograms at the right ventricular (RV) outflow tract and inferior region of the right ventricle. fQRS may reflect the extent of the area of abnormal potentials, but whether the distribution of fQRS has prognostic value is not known.


RESULTS
We evaluated the existence of fQRS in 456 patients with Brugada syndrome, including 117 patients with syncope and 23 patients with VF. The region of fQRS was defined as inferior (II, III, and aVF), lateral (I, aVL, and V5 and V6), anterior (V3 and V4), RV (V1 and V2), and RV outflow tract (V1 and V2 at the third intercostal space). fQRS were present in 229 patients (RV outflow tract in 175, inferior in 135, RV in 90, and lateral in 16 patients). During follow-up (mean 91 months), 39 patients experienced VF. In univariable analyses, fQRS in any distribution and fQRS in each region excluding the RV were associated with VF. Multivariable analysis showed that fQRS in the inferior (hazard ratio, 3.9; confidence interval, 1.9-8.5), lateral (hazard ratio, 3.5; confidence interval, 1.2-8.2), and RV outflow tract (hazard ratio, 2.5; confidence interval, 1.2-5.6) were associated with VF events. The presence of multiple regions of fQRS was associated with worse prognosis.


CONCLUSIONS
The distribution of fQRS is associated with prognosis in Brugada syndrome, further supporting the association of fQRS and arrhythmia substrate.
From the Department of Cardiovascular Therapeutics (H.M., N.N.) and Department of Cardiovascular Medicine (A.W., Y.M., S.K., M.T., K.N., H.I.), Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Japan. hmorita@cc.okayama-u.ac.jp.
Hiroshi
H
Morita
From the Department of Cardiovascular Therapeutics (H.M., N.N.) and Department of Cardiovascular Medicine (A.W., Y.M., S.K., M.T., K.N., H.I.), Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Japan.
Atsuyuki
A
Watanabe
From the Department of Cardiovascular Therapeutics (H.M., N.N.) and Department of Cardiovascular Medicine (A.W., Y.M., S.K., M.T., K.N., H.I.), Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Japan.
Yoshimasa
Y
Morimoto
From the Department of Cardiovascular Therapeutics (H.M., N.N.) and Department of Cardiovascular Medicine (A.W., Y.M., S.K., M.T., K.N., H.I.), Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Japan.
Satoshi
S
Kawada
From the Department of Cardiovascular Therapeutics (H.M., N.N.) and Department of Cardiovascular Medicine (A.W., Y.M., S.K., M.T., K.N., H.I.), Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Japan.
Motomi
M
Tachibana
From the Department of Cardiovascular Therapeutics (H.M., N.N.) and Department of Cardiovascular Medicine (A.W., Y.M., S.K., M.T., K.N., H.I.), Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Japan.
Koji
K
Nakagawa
From the Department of Cardiovascular Therapeutics (H.M., N.N.) and Department of Cardiovascular Medicine (A.W., Y.M., S.K., M.T., K.N., H.I.), Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Japan.
Nobuhiro
N
Nishii
From the Department of Cardiovascular Therapeutics (H.M., N.N.) and Department of Cardiovascular Medicine (A.W., Y.M., S.K., M.T., K.N., H.I.), Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Japan.
Hiroshi
H
Ito
D000328:Adult; D000704:Analysis of Variance; D018780:Body Surface Potential Mapping / Q000379:methods*; D053840:Brugada Syndrome / Q000175:diagnosis* / Q000401:mortality; D015331:Cohort Studies; D016757:Death, Sudden, Cardiac / Q000453:epidemiology*; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D015996:Survival Rate; D013575:Syncope / Q000175:diagnosis / Q000401:mortality; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000401:mortality; D014693:Ventricular Fibrillation / Q000175:diagnosis* / Q000401:mortality
Brugada syndrome; ECG; arrhythmia; fragmented QRS; sudden cardiac death; ventricular fibrillation