Evaluation of autonomic nervous activity in patients with congenital long QT syndrome by an analysis of RR variability

Hiroshi Morita, Hiroshi Yamanari, Tohru Ohe

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11 Citations (Scopus)


Congenital long QT syndrome (LQTS) is a rare hereditary disease characterized by a prolonged QT interval and lethal ventricular tachycardia (Torsades de Pointes: TdP). The pathogenesis of LQTS and the induction of TdP have been thought to be closely related to autonomic nervous abnormalities. We examined autonomic activity in 13 LQTS patients by analyzing heart rate variability from 24 h Holter ambulatory electrocardiographic recordings without medications. In a frequency-analysis of RR variability, we calculated the power in the low-frequency domain (LF) and the high-frequency domain (HF) over 24 h. The ratio of LF to HF (an index of sympathetic nervous activity) was lower in LQTS patients than in controls, whereas HF (an index of parasympathetic nervous activity) was higher. Moreover, LOTS patients with TdP had lower abnormal sympathetic nervous activity than those without TdP. The index of autonomic nervous activity obtained using this method could be useful for evaluating the severity in LQTS.

Original languageEnglish
Pages (from-to)742-748
Number of pages7
Issue number10
Publication statusPublished - Oct 1 1996



  • Autonomic nervous system
  • Long QT syndrome
  • RR variability
  • Torsades de Pointes

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine

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