Action potential alternans in the right ventricular outflow tract in a patient with asymptomatic Brugada syndrome.
A 71-year-old man with frequent ventricular premature contractions after right hip joint surgery was referred to the Cardiology Division. Twelve-lead ECG showed type II Brugada-type ECG and signal-averaged ECG showed positive ventricular late potentials. The 12-lead ECG changed to type I Brugada-type after administration of the class Ic antiarrhythmic drug, pilsicainide. Ventricular fibrillation (VF) was reproducibly induced with double premature stimuli from the right ventricular outflow tract (RVOT) at a basic cycle length (BCL) of 400 ms. Monophasic action potentials (MAPs) recorded from the RVOT at a BCL of 400 ms showed MAP alternans and VF was only induced when extrastimuli were applied after a shorter MAP of the alternans.
Kofune
Masayoshi
M
Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
Watanabe
Ichiro
I
Ashino
Sonoko
S
Ohkubo
Kimie
K
Okumura
Yasuo
Y
Kofune
Tatsuya
T
Nakai
Toshiko
T
Hirayama
Atsushi
A
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000368:Aged; D000889:Anti-Arrhythmia Agents; D053840:Brugada Syndrome / Q000175:diagnosis* / Q000503:physiopathology*; D004562:Electrocardiography; D006801:Humans; D008012:Lidocaine / Q000031:analogs & derivatives; D008297:Male; D014693:Ventricular Fibrillation / Q000175:diagnosis / Q000503:physiopathology; D016278:Ventricular Function, Right / Q000502:physiology*
D000889:Anti-Arrhythmia Agents; D008012:Lidocaine; C042288:pilsicainide