T wave alternans does not assess arrhythmic risk in patients with Brugada syndrome.
BACKGROUND
Brugada syndrome is associated with a risk for sudden death, but the arrhythmic risk in an individual Brugada syndrome patient is difficult to predict. Pathologic changes in the early repolarization phase of the ventricular action potential probably constitute part of the arrhythmogenic substrate in Brugada syndrome. Microvolt T wave alternans (TWA) assesses dynamic beat-to-beat changes in repolarization and has been suggested as a marker for repolarization-related sudden death. We therefore tested whether TWA is an indicator for arrhythmias in Brugada syndrome with a focus on right precordial ECG leads.


METHODS
We assessed TWA in nine symptomatic, inducible patients with established Brugada syndrome and in seven healthy controls. TWA was assessed at rest and during exercise using both standard methods and an algorithm that assesses TWA in the early ST segment and the right precordial leads.


RESULTS
None of the Brugada patients developed TWA in this study irrespective of analysis at rest or during exercise, neither using standard methods nor when the early ST segment was included in the analysis. When the early ST segment was included in the analysis, nonsustained TWA was found in three out of seven, and sustained TWA in one control.


CONCLUSIONS
T wave alternans is not an appropriate test to detect arrhythmic risk in patients with Brugada syndrome.
Kirchhof
Paulus
P
Department of Cardiology and Angiology, University Hospital Münster, Institute of Arteriosclerosis Research at the University of Münster, Germany. kirchhp@uni-muenster.de
Eckardt
Lars
L
Rolf
Sascha
S
Esperer
Hans-D
HD
Paul
Matthias
M
Wichter
Thomas
T
Klein
Helmut U
HU
Breithardt
Günter
G
Böcker
Dirk
D
D000328:Adult; D001145:Arrhythmias, Cardiac / Q000453:epidemiology / Q000628:therapy; D002037:Bundle-Branch Block / Q000453:epidemiology* / Q000628:therapy; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000209:etiology; D017147:Defibrillators, Implantable; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012737:Sex Factors; D013575:Syncope / Q000453:epidemiology / Q000209:etiology; D016896:Treatment Outcome