Ventricular arrhythmia induced by sodium channel blocker in patients with Brugada syndrome.
OBJECTIVE
We administered pilsicainide chloride, a class Ic pure sodium channel blocker, to patients with Brugada syndrome (BS) and evaluated the occurrence of ventricular arrhythmia (VA) and T-wave alternans (TWA).


BACKGROUND
Ventricular arrhythmia and TWA are sometimes induced by a sodium channel blocker challenge test in BS patients, but the significance of the induced VA and TWA is not known.


METHODS
Pilsicainide was administered to 65 patients with BS (10 symptomatic and 55 asymptomatic patients), and the occurrence of VA, TWA, and change of electrocardiogram were evaluated. Electrophysiologic study was performed in 57 patients, and the induction of VA by programmed electrical stimulation (PES) was evaluated.


RESULTS
Ventricular arrhythmia was not induced by administration of pilsicainide in 55 patients (no-VA group). Administration of pilsicainide-induced VA in 10 patients (Pil-VA group) and polymorphic ventricular tachycardia in four patients. Pilsicainide-induced VA in 60% of the symptomatic patients but in only 7% of asymptomatic patients (p < 0.01). ST level, QTc, and indexes of cardiac conduction in the Pil-VA group were not different from those in the no-VA group. Ventricular fibrillation was induced by PES in 67% of the patients in the Pil-VA group and in 33% of the patients in the no-VA group. In six cases, macroscopic TWA occurred in association with pilsicainide-induced VA, but TWA occurred in only one patient without pilsicainide-induced arrhythmia.


CONCLUSIONS
Administration of a sodium channel blocker results in induction of not only ST-elevation but also VA and TWA in patients with BS.
Morita
Hiroshi
H
Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Okayama, Japan. hmorita@cc.okayama-u.ac.jp
Morita
Shiho Takenaka
ST
Nagase
Satoshi
S
Banba
Kimikazu
K
Nishii
Nobuhiro
N
Tani
Yoshinori
Y
Watanabe
Atsuyuki
A
Nakamura
Kazufumi
K
Kusano
Kengo Fukushima
KF
Emori
Tetsuro
T
Matsubara
Hiromi
H
Hina
Kazumasa
K
Kita
Toshimasa
T
Ohe
Tohru
T
D000328:Adult; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D001145:Arrhythmias, Cardiac / Q000139:chemically induced*; D002037:Bundle-Branch Block / Q000503:physiopathology*; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000187:drug effects* / Q000503:physiopathology; D006801:Humans; D008012:Lidocaine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D026941:Sodium Channel Blockers / Q000494:pharmacology*
D000889:Anti-Arrhythmia Agents; D026941:Sodium Channel Blockers; D008012:Lidocaine; C042288:pilsicainide