[A case of congenital long QT syndrome associated with T wave alternans].
A case was presented in which a rare T wave alternans occurred in association with congenital long QT syndrome. A 71-year-old woman, who had experienced several syncopal attacks per year for the previous forty years, was admitted for further evaluation of the syncope. She had a family history of sudden death (sister) and QT prolongation (son). Electrocardiogram showed a corrected QT interval of 0.68 seconds. Treadmill exercise-tolerance test revealed both T wave alternans immediately after exercise and torsades de pointes 150 seconds after exercise. The syncope was induced by the mental excitation. A prolonged corrected QT interval reduced from 0.70 seconds to 0.58 seconds by the correction of her serum potassium and magnesium. The effect of propranolol, verapamil, phenytoin or mexiletine on T wave alternans and ventricular arrhythmia was evaluated by the treadmill exercise-tolerance test. The treatment with propranolol was most effective.
Division of Cardiology, Yamada Red Cross Hospital.
M
M
Motoyasu
H
H
Nishikawa
Y
Y
Shimizu
T
T
Aoki
N
N
Ono
M
M
Unno
Y
Y
Kakuta
T
T
Yazu
A
A
Kasai
T
T
Yamakado
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006801:Humans; D008133:Long QT Syndrome / Q000151:congenital* / Q000188:drug therapy / Q000503:physiopathology; D011433:Propranolol / Q000627:therapeutic use; D013575:Syncope / Q000188:drug therapy / Q000209:etiology; D016171:Torsades de Pointes / Q000188:drug therapy / Q000209:etiology
D000319:Adrenergic beta-Antagonists; D011433:Propranolol