Heart Rate Variability and Autonomic Activity in Patients Affected with Rett Syndrome |
Deok Young Choi1, Jin Ha Chang1, Hee Jung Chung2 |
1Department of Pediatrics, College of Medicine, Yonsei University, Seoul, Korea 2Department of Pediatrics, National Health Insurance Cooperation, Ilsan Hospital, Koyang, Korea |
Rett 증후군 환자에서의 자율신경 활성도 및 심박수 변이도 측정 |
최덕영1, 장진하1, 정희정2 |
1연세대학교 의과대학 소아과학교실 2국민건강보험공단 일산병원 소아과 |
Correspondence:
Hee Jung Chung, Email: agathac@nhimc.or.kr |
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Abstract |
Purpose : In Rett syndrome patients, the incidence of sudden death is greater than that of the general population, and cardiac electrical instability including fatal cardiac arrhythmia is a main suspected cause. In this study, we are going to find out the possible cause of the higher risk of sudden death in Rett patients by the evaluation of heart rate variability, a marker of cardiac autonomic activity and corrected QT intervals.
Methods : Diagnosis of Rett syndrome was made by molecular genetic study of Rett syndrome (MECP2 gene) or clinical diagnostic criteria of Rett syndrome. Heart rate variability and corrected QT intervals were measured by 24 h-Holter study in 12 Rett patients, and in 30 age-matched healthy children with chief complaints of chest pain or suspected heart murmurs. The were compared with the normal age-matched control.
Results : Patients with total Rett syndrome, classic Rett syndrome, and Rett variants had significantly lower heart rate variability(especially rMSSD)(P<0.05) and longer corrected QT intervals than age-matched healthy children(P<0.05). Sympathovagal balance expressed by the ratio of high to low frequency(LF/HF ratio) also showed statistically significant differences between the three groups considered(P<0.05).
Conclusion : A significant reduction of heart rate variability, a marker of autonomic disarray, suggests a possible explanation of cardiac dysfunction in sudden death associated with Rett syndrome. |
Key Words:
Rett syndrome, Heart rate variability, Cardiac dysautonomia, Sudden death |
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