Early afterdepolarization in a patient with complete atrioventricular block and torsades de pointes.
We present a patient with complete atrioventricular block and torsades de pointes in whom early afterdepolarization (EAD) was demonstrated in right ventricular monophasic action potentials (MAPs). In an emergency situation, MAPs were recorded after the suppression of torsades de pointes by magnesium injection. EADs were observed at three out of five right ventricular sites during escape rhythm. Thus, magnesium abolished the tachycardia without shortening the QT interval and probably without suppressing EAD. Right ventricular pacing and the injection of lidocaine (50 mg) suppressed EAD and shortened the QT interval.
Kurita
T
T
Division of Cardiology, National Cardiovascular Center, Osaka, Japan.
Ohe
T
T
Shimizu
W
W
Hotta
D
D
Shimomura
K
K
D000200:Action Potentials / Q000502:physiology; D000368:Aged; D001919:Bradycardia / Q000503:physiopathology; D002304:Cardiac Pacing, Artificial; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006327:Heart Block / Q000175:diagnosis / Q000503:physiopathology*; D006329:Heart Conduction System / Q000187:drug effects / Q000503:physiopathology*; D006801:Humans; D008012:Lidocaine / Q000627:therapeutic use; D008278:Magnesium Sulfate / Q000627:therapeutic use; D016171:Torsades de Pointes / Q000175:diagnosis / Q000188:drug therapy / Q000503:physiopathology*
D008278:Magnesium Sulfate; D008012:Lidocaine