24 Hours Heart Rate Variability in Elderly Hypertensive Patients

ABSTRACT

BACKGROUND: Heart Rate Variability help us to diagnose the impairment of autonomic nervous system in patients with diabetes, hypertension, ischemic heart disease, chronic renal disease, and arrhythmia. Change of autonomic nervous system is related to circadian rhythm, stress, physical activity, and so on. Especially, impairment of vagal nervous system with age help us to expect sudden cardiac death, myocardial infarction, and arrhythmia. So we survey heart rate variability by using 24 hours holter monitoring to expect impairment of autonomic nervous system in elderly hypertensive patients. METHODS: In order to assess 24 hours heart rate variability, we use Del Mar Avionics 563 holter monitoring on 11 elderly hypertensive patients( > or =65 years), 12 younger hypertensive patients( <65 years), and 15 normal subjects. RESULTS: 1) Standard deviation of mean R-R interval, LF(low frequency), HF(high frequency), TPSD(total power spectral density) are more decreased in elderly hypertensive patients than in younger hypertensive patients in 24 hours health rate variability analysis(t-test p<0.05). 2) According to age, elderly control group had lower LF power spectral parameter than younger control group had, but other parameters were not decreased, and elderly hypertensive group had lower LF, HF, TPSD, SD of mean R-R interval than younger hypertensive group did(p<0.05). 3) In circardian rhythm, normal subjects had high HF power spectral parameter and low LF power spectral parameter at evening and night. On the other hand, elderly hypertensive group had constant low level of LF, HF power spectral parameter during the day and night. CONCLUSIONS: On heart rate variability analysis using by 24 hours Holter monitoring, heart rate variability was decreased, and impairment of autonomic nervous system was accelerated in elderly hypertensive patients.