AUDITORY-STIMULI AS A MAJOR CAUSE OF SYNCOPE IN A PATIENT WITH IDIOPATHIC LONG QT SYNDROME

A 35-year-old woman was hospitalized due to frequent attacks of syncop e immediately after the ringing of a bell or alarm clock. Her standard electrocardiograms showed a long QT interval (QTc=0.56 s) with a biza rre T-wave inversion in precordial leads. After admission, a total of 9 events of syncope were observed, Malignant ventricular tachyarrhythm ia (torsade de pointes, ventricular flutter or fibrillation) was recor ded during each episode, and DC shock was required to abolish such tac hyarrhythmias on 3 occasions. On monitored electrocardiograms, an addi tional 8 events of ventricular tachycardia without syncope were also d etected. Auditory stimuli appeared to be involved in the initiation of malignant ventricular arrhythmia. Immediately after auditory stimuli, changes in the QT interval and T-wave morphology resulted in ventricu lar premature beats, leading to ventricular tachycardia. The episodes of syncope or malignant ventricular arrhythmia were frequently observe d early in the morning and near midnight. She had been treated with va rious types of antiarrhythmic agents, and propranolol was the most eff ective in preventing ventricular arrhythmia. These findings indicate t hat auditory stimuli may cause ventricular arrhythmia and subsequent c ardiac syncope, or even sudden cardiac death, in some patients with lo ng QT syndrome.