Clinical research
QT-interval prolongation inright precordial leads: an additional electrocardiographic hallmark of Brugada syndrome

https://doi.org/10.1016/j.jacc.2003.07.005Get rights and content
Under an Elsevier user license
open archive

Abstract

Objectives

The aim of this study was to evaluate whether the occurrence of the Brugada Syndrome typical electrocardiogram (ECG) pattern (i.e., right bundle branch block, coved-type ST-segment elevation, and T-wave inversion in the right precordial leads) is characterized by a concomitant lengthening of QT intervals in the right precordial leads.

Background

It has been suggested that the typical ECG pattern of Brugada syndrome is due to a decreased net inward current during phase 1 of the action potential, which also leads to its prolongation in the right epicardium.

Methods

Thirty-two subjects (19 males) age 37 ± 15 years with a suspicious baseline ECG, or who were relatives of Brugada syndrome patients, underwent 12-lead ECG before and after the administration of flecainide.

Results

The flecainide test was negative in 14 and positive in 18 subjects. After flecainide administration, the positive ECGs were characterized by a greater QT interval corrected for heart rate (QTc) prolongation in the right precordial leads than that in the negative ECGs (78.2 ± 35.5 ms vs. 22.0 ± 28.4 ms in V1and 107.1 ± 43.8 ms vs. 26.7 ± 30.1 ms in V2; p < 0.01), whereas there was no difference in the QTc prolongation in the left precordial leads (55.2 ± 25.3 ms vs. 35.1 ± 28.1 ms in V5and 53.1 ± 32.8 ms vs. 27.3 ± 22.4 ms in V6; p = NS).

Conclusions

In accordance with the electrophysiological background, the typical ECG pattern of Brugada syndrome is also characterized by a considerable prolongation of the QT interval in right precordial leads.

Abbreviations

AP
action potential
ICC
intraclass correlation coefficient
PCR
polymerase chain reaction
QTc
QT interval corrected for heart rate
ROC
receiver operator characteristics
SSCP
single-strand conformation polymorphism

Cited by (0)