Variable electrocardiographic effects of short-term quinidine sulfate administration in Brugada syndrome.
Quinidine, a class I antiarrhythmic agent with blocking property of transient outward current, is a possible candidate for the suppression of ventricular fibrillation in patients with Brugada syndrome; although there is a concern that its ability to these effects may be proarrhythmic. Therefore, we evaluated the effect of quinidine sulfate on ST-segment elevation in Brugada syndrome. In 8 patients with Brugada syndrome, the magnitude of ST-elevation at the J-point (ST(J)), and the ST-segment configuration in leads V1-V3, were compared before and on day 2 after the initiation of quinidine administration. In 3 patients, quinidine attenuated ST(J) by > or = 0.1 mV. Of these 3 patients, ST-segment elevation was normalized in 2 patients, while the ST-segment configuration was unchanged in another. In another 3 patients, quinidine augmented ST(J) by > or = 0.1 mV without any change of ST-segment configuration, and the augmentation was returned to baseline after the discontinuation of quinidine. Quinidine exhibited no effect on the ST-segment in the remaining 2 patients. The favorable effects of quinidine on the ST-segment tended to be more pronounced in patients with prominent ST-elevation at baseline. In 1 patient, quinidine was effective in eliminating both ST-segment elevation and repetitive tachyarrhythmia episodes. In conclusion, the effects of quinidine on ST-segment elevation were variable. Quinidine may potentially augment the ST-segment elevation in some patients with Brugada syndrome.
Watanabe
Hiroshi
H
Division of Cardiology, Niigata University Graduate School of Medical and Dental Science, Asahimachidori, Niigata, Japan. hiroshi7@med.niigata-u.ac.jp
Chinushi
Masaomi
M
Washizuka
Takashi
T
Sugiura
Hirotaka
H
Hirono
Takashi
T
Komura
Satoru
S
Hosaka
Yukio
Y
Yamaura
Masayuki
M
Tanabe
Yasutaka
Y
Furushima
Hiroshi
H
Fujita
Satoru
S
Aizawa
Yoshifusa
Y
D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage*; D002037:Bundle-Branch Block / Q000503:physiopathology*; D004562:Electrocardiography / Q000187:drug effects*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D011802:Quinidine / Q000008:administration & dosage*; D013575:Syncope; D013577:Syndrome; D014693:Ventricular Fibrillation / Q000188:drug therapy
D000889:Anti-Arrhythmia Agents; D011802:Quinidine