Intracoronary acetylcholine-induced prolongation of the QT interval and Torsade des Pointes in long QT interval syndrome.
A 75-year-old female had syncopal episodes from Torsade des Pointes (TdP). Her electrocardiogram showed a prolonged QT interval which was not associated with electrolyte imbalances or drug therapy. Similar electrocardiographic abnormalities were found in three family members. Electrophysiologic study showed a mildly prolonged effective refractory period of 260-290 msec, but no tachyarrhythmia was induced. Coronary arteriography was normal but intracoronary acetylcholine unexpectedly induced a prolongation of the QT interval and TdP. Direct action of acetylcholine on the ventricular muscle was suggested.
Aizawa
Y
Y
First Department of Internal Medicine, Niigata University School of Medicine, Japan.
Matsubara
T
T
Higuchi
K
K
Washizuka
T
T
Tamura
Y
Y
Uchiyama
H
H
Igarashi
Y
Y
Shibata
A
A
D000109:Acetylcholine / Q000008:administration & dosage / Q000009:adverse effects*; D000200:Action Potentials; D000368:Aged; D017023:Coronary Angiography; D003331:Coronary Vessels; D004562:Electrocardiography; D004594:Electrophysiology; D005260:Female; D006801:Humans; D008133:Long QT Syndrome / Q000139:chemically induced / Q000235:genetics / Q000503:physiopathology*; D012032:Refractory Period, Electrophysiological; D013564:Sympathetic Nervous System / Q000502:physiology; D016171:Torsades de Pointes / Q000139:chemically induced* / Q000503:physiopathology
D000109:Acetylcholine