Heart rate variability and analysis of rhythm in patients with restless legs syndrome

Restless legs syndrome (RLS) is a sleep disorder that characterized with request and act of movement accompanying abnormal sensations in extremities. RLS, which etiology is unknown and more frequent in female and middle and advance ages, encumbers to individuals and community by reducing quality of life and labor force. It is suggested that RLS causes serious mortality and morbidity due to affecting cardiovascular system by unknown mechanisms besides its social problems in patients. Community based studies showed that RLS is a risk factor for cardiovascular diseases. Probable cause of increased cardiovascular risk is sympathetic activity. In this paper increased sympathomimetic activity in RLS patients have been studied with variability analysis. The data examined in this study SDNN, SDANN, SDNNi, RMMSD,PNN50 values give information about sinus node and hormonal stimulus in this node with time based RR intervals variation. HF, LF, VLF give information about frequency based RR intervals variation. HF is an indicator of regulatory effect of parasympathetic activity depending onthe ventilation in normal sinus rhythm. LF gives information about combinations ofsympathetic and parasympathetic responses in barorefleks activity which the sympathetic system is slightly dominant. Although the physiological response of VLF is not clearly known, it is considered that VLF is related to reflex responses of parasympathetic and renin-angiotensin systems due to physical activity in long term records. The rate of LF/HF is used as an index of sympathovagal balance.Sixty five new diagnosed RLS patients and 58 control group patients which has similar age and sex are included in this study. Demographic data and KHD analysis data were compared in groups. Among demographic characteristics, in RLS patient group thyroid disease was only detected in higher rates. In the comparison of HRV figures of patient and control group, some differences in the SDNN amount were detected. When classified and compared as slightly and severe according to the RLS patients? severity; meaningful variations were detected in LF night, VLF total-night and day, and the total 48power figures. When severe RLS group was compared with the control group, meaningful variations were detected in SDHH night, SDNNİ and VLF night figures. When sligthly RLS patients are compared with control group, there is no statistical variations when corralation between disease process and analysis data is examined. This study, which considered with the other studies in literature, supports increased cardiovascular risk due to increased sympathetic system activation but does not clarify this situation. Further large studies needed to evaluate sympathetic system within other tests included