title: Cardiac repolarization abnormalities and increased sympathetic activity in scleroderma.
abstract: BACKGROUND
  Cardiac involvement in scleroderma is a poor prognostic sign and is usually underdiagnosed, particularly in asymptomatic patient. This paper focuses on QT dynamicity and heart rate variability (HRV) in patients with scleroderma and controls in an attempt to investigate the cardiac autonomic system and ventricular repolarization.
  
  
  METHODS
  Sixty patients with scleroderma and 30 age- and sex-matched healthy controls who had no cardiovascular risk factors were included in this study. All patients and the controls underwent a 24-hour holter recording as well as a transthoracic echocardiography. HRV and QT dynamicity parameters were calculated.
  
  
  RESULTS
  In HRV analysis, autonomic balance was changed in favor of the sympathetic system in patients with diffuse scleroderma. In QT dynamicity analysis, QT/RR slopes were significantly steeper in patients with diffuse scleroderma compared to patients with limited scleroderma and controls (QTapex/RR: 0.24 +/- 0.16, 0.15 +/- 0.03, 0.14 +/- 0.03 respectively p < 0.001; QTend/RR: 0.26 +/- 0.17, 0.14 +/- 0.04, 0.13 +/- 0.05, respectively p < 0.001).
  
  
  CONCLUSIONS
  Patients with diffuse scleroderma may have asymptomatic cardiac repolarization abnormalities and autonomic dysfunction. Our results may indicate that QT dynamicity and HRV can be useful noninvasive methods that may detect impaired state of autonomic balance and cardiac repolarization in patients with diffuse scleroderma.
authors: Department of Cardiology, Faculty of Medicine, Hacettepe University, Ankara, Turkey.
authors: Orcun
authors: O
authors: Ciftci
authors: Ahmet Mesut
authors: AM
authors: Onat
authors: Bunyamin
authors: B
authors: Yavuz
authors: Ali
authors: A
authors: Akdogan
authors: Kudret
authors: K
authors: Aytemir
authors: Lale
authors: L
authors: Tokgozoglu
authors: Levent
authors: L
authors: Sahiner
authors: Ali
authors: A
authors: Deniz
authors: Kemal
authors: K
authors: Ureten
authors: Guler
authors: G
authors: Kizilca
authors: Meral
authors: M
authors: Calguneri
authors: Ali
authors: A
authors: Oto
mesh_terms: D001145:Arrhythmias, Cardiac / Q000209:etiology*; D016022:Case-Control Studies; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012595:Scleroderma, Systemic / Q000150:complications* / Q000503:physiopathology; D013564:Sympathetic Nervous System / Q000503:physiopathology*