Spontaneous Onset of Torsade de Pointes in Long-QT Syndrome and the Role of Sympathovagal Imbalance.
Open Access
- 1 January 2001
- journal article
- case report
- Published by Japanese Circulation Society in Japanese Circulation Journal
- Vol. 65 (12), 1087-1090
- https://doi.org/10.1253/jcj.65.1087
Abstract
The net effects of sympathetic and vagal activity on the QT interval and the mode of spontaneous onset of torsade de pointes (TdP) are still unclear in long-QT syndrome. Two patients with long-QT syndrome had syncope while undergoing Holter ECG investigation. The spontaneous onset of TdP in these patients was analyzed with respect to the relation between the RR and QT intervals. Both patients were high-school students (16- and 17-year-old boys) who had been diagnosed as long-QT syndrome and followed up without medical treatment because they had had neither a history of syncope nor arrhythmia induction by treadmill exercise tests. The first episode of syncope in both patients occurred during ordinary daily life and was not related to exercise or psychological stress. The dynamic changes between the RR and QT intervals associated with the spontaneous onset of TdP were analyzed by Holter ECG. Both patients showed sinus tachycardia followed by abrupt sinus bradycardia immediately before the onset of TdP. The enhanced rate of the adaptive response of the QT interval that occurred during the deceleration of the heart rate preceded the onset of TdP. These observations suggest that the complex situation that follows sympathovagal imbalance may have an important role in the dynamic change in the QT interval and initiation of TdP in patients with long-QT syndrome. (Jpn Circ J 2001; 65: 1087 - 1090)Keywords
This publication has 17 references indexed in Scilit:
- Auditory stimuli as a trigger for arrhythmic events differentiate HERG-related (LQTS2) patients from KVLQT1-related patients (LQTS1)Journal of Invasive Cardiology, 1999
- Relation Between Autonomic Nerve Activity and QT Interval in Patients with Congenital Long QT Syndrome: Analysis Using 24‐Hour Holter ECG MonitoringAnnals of Noninvasive Electrocardiology, 1998
- Time- and Rate-Dependent Alterations of the QT Interval Precede the Onset of Torsade de Pointes in Patients With Acquired QT ProlongationJournal of Invasive Cardiology, 1997
- Mode of onset of torsade de pointes in congenital long QT syndromeJournal of Invasive Cardiology, 1996
- Spontaneous sequences of onset of torsade de pointes in patients with acquired prolonged repolarization: Quantitative analysis of Holter recordingsJournal of Invasive Cardiology, 1995
- Cardiac Arrhythmias and the Autonomic Nervous SystemJournal of Cardiovascular Electrophysiology, 1993
- The long QT syndrome. Prospective longitudinal study of 328 families.Journal of the American College of Cardiology, 1991
- The long QT interval syndrome. A Rosetta stone for sympathetic related ventricular tachyarrhythmias.Journal of the American College of Cardiology, 1991
- Differences in the electrophysiological response of canine ventricular subendocardium and subepicardium to acetylcholine and isoproterenol. A direct effect of acetylcholine in ventricular myocardium.Circulation Research, 1990
- Influence of heart rate and inhibition of autonomic tone on the QT interval.Journal of the American College of Cardiology, 1982