Comparison of conduction delay in the right ventricular outflow tract between Brugada syndrome and right ventricular cardiomyopathy: investigation of signal average ECG in the precordial leads.
BACKGROUND
In both Brugada syndrome (BS) and arrhythmogenic right ventricular cardiomyopathy (ARVC), electrical abnormalities in the right ventricular outflow tract (RVOT) are important for arrhythmogenesis.


OBJECTIVE
The aim of this study was to compare conduction delay in the right ventricular in BS with that in ARVC using the signal-averaged electrocardiogram.


METHODS
Twenty patients with BS (18 men and 2 women; 55 +/- 12 years old; 9 symptomatic and 11 asymptomatic) and eight patients with ARVC (six men and two women; 53 +/- 16 years old) were included. We assessed the presence of late potentials (LPs) and the filtered QRS duration (fQRSd) in V(2) and V(5) using a high-pass filter of 40 Hz (fQRSd:40) and 100 Hz (fQRSd:100).


RESULTS
In ARVC, there was no significant difference in fQRSd:40 between V2 and V5 (158 +/- 19 vs. 145 +/- 17 ms, respectively): however, in BS, fQRSd:40 in V2 was significantly longer than fQRSd:40 in V5 (147 +/- 15 vs. 125 +/- 10 ms, P < 0.001). In ARVC, there was no significant difference between fQRSd:40 and fQRSd:100 in V(2) and V(5) (158 +/- 19 vs. 142 +/- 23 ms and 145 +/- 17 vs. 132 +/- 9 ms, respectively). In contrast, in BS, fQRSd:100 was significantly shorter than fQRSd:40 in V2 (110 +/- 8 ms vs. 147 +/- 15, P < 0.001). The relative decrease in fQRSd:100 compared with fQRSd:40 in V2 was significantly greater in BS than in ARVC.


CONCLUSIONS
The dominant prolongation of the fQRSd in the right precordial lead in BS was different from the characteristics of ARVC, which may be caused by the conduction delay due to fibro-fatty replacement in RV.
Furushima
Hiroshi
H
The First Department of Internal Medicine, Niigata University School of Medicine, 1-754 Asahi-machi-dori, Niigata, 951-8510, Japan. chimiri@med.niigata-u.ac-jp
Chinushi
Masaomi
M
Okamura
Kazuki
K
Iijima
Kenichi
K
Komura
Satoru
S
Tanabe
Yasutaka
Y
Okada
Shinsuke
S
Izumi
Daisuke
D
Aizawa
Yoshifusa
Y
D000328:Adult; D000368:Aged; D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000175:diagnosis*; D053840:Brugada Syndrome / Q000175:diagnosis*; D002320:Cardiovascular Physiological Phenomena; D004562:Electrocardiography / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted; D018497:Ventricular Dysfunction, Right / Q000175:diagnosis; D014693:Ventricular Fibrillation