Noninvasive risk stratification of subjects with a Brugada-type electrocardiogram and no history of cardiac arrest.
BACKGROUND
Recent studies suggest that the Brugada-type electrocardiogram (ECG) is much more prevalent than the manifest Brugada syndrome. Although invasive electrophysiologic investigations have been proposed as a risk stratifier, their value is controversial, and alternative noninvasive techniques may be preferred. We sought a noninvasive strategy to detect a high-risk group in a long-term follow-up study of subjects with a Brugada-type ECG, and no history of cardiac arrest.


METHODS
This study enrolled 124 consecutive subjects with a Brugada-type ECG. Prognostic indices included: age, sex, a family history of sudden death, syncopal episodes, a spontaneous coved-type ST-segment elevation, maximal magnitude of ST-segment elevation, a spontaneous change in ST segment, a mean QRS duration, maximal QT interval, QT dispersion, late potentials (LP) by signal-averaged ECG, and microvolt T-wave alternans.


RESULTS
Of the 124 subjects, 20 consenting subjects had an implantable defibrillator before follow-up. During a 40 +/- 19-month follow-up, 12 subjects (9.7%) reached one of the endpoints (sudden death or ventricular tachyarrhythmia). Of the 12 risk indices, a family history of sudden death, syncopal episodes, a spontaneous coved-type ST-segment elevation, a spontaneous change in ST segment, and LP had significant values. In multivariate analysis, a spontaneous change in ST segment had the most significance (a relative hazard, 9.2; P = 0.036). Combined assessment of this index and other significant indices obtained higher positive predictive values (43-71%).


CONCLUSIONS
A spontaneous change in ST segment is associated with the highest risk for subsequent events in subjects with a Brugada-type ECG. The presence of syncopal episodes, a history of familial sudden death, and/or LP may increase its value.
Ikeda
Takanori
T
Cardiac Electrophysiology Lab, Second Department of Internal Medicine, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo 181-8611, Japan. iket@kyorin-u.ac.jp
Takami
Mitsuaki
M
Sugi
Kaoru
K
Mizusawa
Yuka
Y
Sakurada
Harumizu
H
Yoshino
Hideaki
H
D000328:Adult; D017677:Age Distribution; D002037:Bundle-Branch Block / Q000175:diagnosis* / Q000401:mortality*; D015897:Comorbidity; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D018572:Disease-Free Survival; D004562:Electrocardiography / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D006323:Heart Arrest / Q000175:diagnosis / Q000401:mortality; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D011379:Prognosis; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D017678:Sex Distribution; D015996:Survival Rate; D014693:Ventricular Fibrillation / Q000175:diagnosis* / Q000401:mortality*