title: Autonomic modulation in hypertension without hypertrophy.
abstract: OBJECTIVE
  Cardiac autonomic modulation and baroreflex sensitivity are altered in individuals with essential hypertension. Hypertension is considered as a strong and independent risk factor for supraventricular and ventricular arrhythmias. The aim of the present study was to evaluate cardiac autonomic control and the arrhythmogenic risk by using 24-h heart rate variability (HRV) and heart rate turbulence (HRT) analysis in essential hypertension without left ventricular hypertrophy (LVH).
  
  
  METHODS
  Fifty-eight newly diagnosed untreated hypertensive patients without LVH (mean age 51 ± 12 years, 26 women) and 56 adult, healthy volunteers (mean age 49 ± 12 years, 24 women) were included in the study. Subjects with secondary causes of hypertension or autonomic dysfunction were excluded. The diagnosis of hypertension was based on ambulatory blood pressure monitoring results. Time-domain HRV parameters and HRT parameters were calculated from 24-hour Holter recordings.
  
  
  RESULTS
  Values of SDNN and SDANN in the hypertension group were significantly lower than in the control group (P < 0.01 and P < 0.01, respectively). At least one of the turbulence onset (TO) and turbulence slope (TS) values were found abnormal in 10 of 32 hypertensive patients and in 5 of 24 control individuals (P = 0.38). There was no significant difference between HRT parameters, TO and TS (P = 0.67 and P = 0.12, respectively).
  
  
  CONCLUSIONS
  Sympathetic tone begins to increase in hypertension before LVH develops. However, the impact of this increase on HRT is not clear. There is a need for further research to investigate the impact of hypertension and LVH on HRT.
authors.forename: Celal
authors.initials: C
authors.lastname: Kilit
authors.forename: Turkan
authors.initials: T
authors.lastname: Pasali Kilit
authors.forename: Ersel
authors.initials: E
authors.lastname: Onrat
mesh_terms: D001341:Autonomic Nervous System / Q000503:physiopathology*; D018660:Blood Pressure Monitoring, Ambulatory; D002312:Cardiomyopathy, Hypertrophic; D018450:Disease Progression; D015716:Electrocardiography, Ambulatory; D000075222:Essential Hypertension; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors
keywords: Autonomic dysfunction; heart rate turbulence; heart rate variability; hypertension