title: Spatial QRS-T angle in peritoneal dialysis patients: association with carotid artery atherosclerosis, coronary artery calcification and troponin T.
abstract: BACKGROUND
  Abnormal values of the spatial angle between the directions of ventricular depolarization and repolarization (QRS-T) predict potently arrhythmic events and mortality in various patients groups. The study was designed to estimate QRS-T in a group of peritoneal dialysis (PD) patients, and to assess the possible association between QRS-T and coronary artery calcification (CAC), atherosclerosis, and some biochemical measurements.
  
  
  METHODS
  The angular differences between the maximum spatial QRS and T vectors were reconstructed from ECGs in 57 selected PD patients and in 54 controls. In patients CAC score was performed by using multi-row computed tomography. Atherosclerotic disease was assessed by measuring carotid arteries' intima-media thickness (IMT) and plaque score (sum of the maximum thicknesses in mm of all plaques on both sides) by using an ultrasound scanner.
  
  
  RESULTS
  QRS-T was higher in patients compared with controls (34.79% B111.97 and 14.95% B17.87 respectively; P < 0.001). Median CAC score equalled 104.5 Agatson units (Au) (range, 0-2478). IMT was 0.832% B10.208, and atherosclerotic plaques were detected in 82.5% of patients. The plaque score was 7.97% B14.49. QRS-T was higher in patients with CAC score >400 Au compared with patients with CAC score <400 Au (P = 0.011). The results of univariate linear regression analysis showed correlation between QRT-T and dialysis duration (r = 0.305, P = 0,020), LVMI (r = 0.311, P = 0.017), HDL (r = -0.361, P = 0.006), cTnT (r = 0.442, P < 0.001), plaque score (r = 0.403, P = 0.001) and CAC score (r = 0.451, P < 0.001). On multivariate analysis, CAC score, plaque score and troponine T were found to be independent predictors of QRS-T values.
  
  
  CONCLUSIONS
  QRS-T is high in PD patients and is mainly associated with coronary artery calcium burden, atherosclerosis and troponin T elevation. The possible clinical importance of the higher QRS-T in PD patients remains to be confirmed in further studies.
authors.affiliation: Nephrology Department, Medical University of Lublin, 20-950 Lublin, ul Jaczewskiego 8, Poland. jaroszynskiaj@interia.pl
authors.forename: Andrzej
authors.initials: A
authors.lastname: Jaroszynski
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Czekajska-Chechab
authors.forename: Anna
authors.initials: A
authors.lastname: Drelich-Zbroja
authors.forename: Tomasz
authors.initials: T
authors.lastname: Zapolski
authors.forename: Andrzej
authors.initials: A
authors.lastname: Ksiazek
mesh_terms: D000328:Adult; D050197:Atherosclerosis / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D002114:Calcinosis / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D002340:Carotid Artery Diseases / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis; D020107:Troponin T / Q000097:blood; D014672:Vectorcardiography
chemical_list: D020107:Troponin T