Sodium channel blockers enhance the temporal QT interval variability in the right precordial leads in Brugada syndrome.

Abstract

BACKGROUND:

Temporal QT interval variability is associated with sudden cardiac death. The purpose of this study was to evaluate temporal QT interval variability in Brugada syndrome (BS).

METHODS:

We measured QT and RR intervals in precordial leads (V(1)-V(6)) based on 12-beat resting ECG recordings from 16 BS patients (B group) with spontaneous ST elevation in right precordial leads (V(1)-V(2)) and from 10 patients with normal hearts (C group). We measured the response in B group before and after administration of pilsicainide (1 mg/kg). The standard deviation (QT-SD, RR-SD) of the time domain and total frequency power (QT-TP, RR-TP) were calculated for all precordial leads, and the latter was to analyze the frequency domain.

RESULTS:

The right precordial leads in BS exhibited an additional and prominent ST elevation (coved-type) after pilsicainide administration. Both QT-SD and QT-TP values were significantly more increased in B, than in C (5.1 +/- 1.2 vs 3.6 +/- 0.2 and 23.4 +/- 2.9 vs 12.3 +/- 1.7 msec(2), P < 0.01, respectively) and after pilsicainide administration in B. (5.1 +/- 0.4 vs 3.9 +/- 0.3, 25.8 +/- 3.4 vs 16.3 +/- 2.6 msec(2), P < 0.01, respectively) However, QT-SD and QT-TP did not significantly change in any of other leads (V(3)-V(6)) and RR-SD and RR-TP were similar for both groups, as well as after intravenous pilsicainide administration in B.

CONCLUSIONS:

The temporal QT interval variability was identified in BS. Moreover, sodium channel blocker induced temporal fluctuation in QT interval and it may possibly provide a substrate for ventricular arrhythmia in BS patients.

• Authors: Tetsuzou Kanemori, Hiroki Shimizu, Katsumi Oka, Yoshio Furukawa, Kenji Hiromoto, Takanao Mine, Tohru Masuyama, Mitsumasa Ohyanagi
• Journal: Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc (Ann Noninvasive Electrocardiol) Vol. 13 Issue 1 Pg. 74-80 (Jan 2008) ISSN: 1082-720X [Print] United States
• PMID: 18234009 (Publication Type: Controlled Clinical Trial, Journal Article)

Chemical References

• Sodium Channel Blockers
• Lidocaine
• pilsicainide

Topics

• Brugada Syndrome (diagnosis, physiopathology)
• Electrocardiography (drug effects, methods)
• Electrophysiologic Techniques, Cardiac (methods, statistics & numerical data)
• Female
• Heart Rate (drug effects)
• Humans
• Lidocaine (analogs & derivatives, pharmacology)
• Male
• Middle Aged
• Sodium Channel Blockers (pharmacology)
• Time Factors