title: Time domain heart rate variability analysis in patients with thalassaemia major.
abstract: OBJECTIVE
  Cardiac complication is one of the major causes of death in patients with thalassaemia major. Heart rate variability is a non-invasive index of neuronal modulation of heart rate. In this study, autonomic functions of the heart in a preclinical stage of heart disease were evaluated in 48 thalassaemic patients with time domain heart rate variability analysis; the control group consisted of 45 healthy subjects.
  
  
  RESULTS
  Mean RR time in the study and control group was 0.73 +/- 0.1, and 0.82 +/- 0.1 ms respectively (p < 0.001). In the study group; SDNN, SDNN-i, SDANN-i, RMSSD, and PNN50 were found to be 167.4 +/- 86.2 ms, 153.9 +/- 108.1 ms, 111.4 +/- 60.4 ms, 108.9 +/- 86.7 ms, and 14.5 +/- 13.4%, respectively. Time domain parameters were significantly lower in the study group than the control group (p < 0.00 1). There was a significant positive correlation between the mean RR time and SDNN, SDNN-i, SDANN-i, RMSSD, and PNN50 (for the RMSSD p < 0.05, r = 0.31; for the others p = 0.000, and r values were 0.65, 0.65, 0.38, 0.37 for the SDNN, SDNN-i, SDANN-i, and PNN50, respectively).
  
  
  CONCLUSIONS
  The analysis of heart rate variability might be helpful to detect cardiac complications in the preclinical stage of the cardiac involvement.
authors.affiliation: Paediatric Cardiology, Ege University Faculty of Medicine, Department of Pediatrics, Izmir, Turkey. dolunayk@yahoo.com
authors.forename: Dolunay
authors.initials: D
authors.lastname: Gurses
authors.forename: Zülal
authors.initials: Z
authors.lastname: Ulger
authors.forename: Ertürk
authors.initials: E
authors.lastname: Levent
authors.forename: Yeşim
authors.initials: Y
authors.lastname: Aydinok
authors.forename: A Ruhi
authors.initials: AR
authors.lastname: Ozyurek
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015716:Electrocardiography, Ambulatory; D005260:Female; D005293:Ferritins / Q000378:metabolism; D006339:Heart Rate; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008297:Male; D013318:Stroke Volume; D013997:Time Factors; D016277:Ventricular Function, Left; D017086:beta-Thalassemia / Q000097:blood / Q000503:physiopathology*
chemical_list: D015415:Biomarkers; D006454:Hemoglobins; D005293:Ferritins