title: Short-term effect of percutaneous recanalization of chronic total occlusions on QT dispersion and heart rate variability parameters.
abstract: BACKGROUND
  QT dispersion (QTd), which is a measure of inhomogeneity of myocardial repolarization, increases following impaired myocardial perfusion. Its prolongation may provide a suitable substrate for life-threatening ventricular arrhythmias. We investigated the changes in QTd and heart rate variability (HRV) parameters after successful coronary artery revascularization in a patient with chronic total occlusions (CTO).
  
  
  METHODS
  This study included 139 successfully revascularized CTO patients (118 men, 21 women, mean age 58.3±9.6 years). QTd was measured from a 12-lead electrocardiogram and was defined as the difference between maximum and minimum QT interval. HRV analyses of all subjects were obtained. Frequency domain (LF: HF) and time domain (SDNN, pNN50, and rMSSD) parameters were analyzed. QT intervals were also corrected for heart rate using Bazett's formula, and the corrected QT interval dispersion (QTcd) was then calculated. All measurements were made before and after percutaneous coronary intervention (PCI).
  
  
  RESULTS
  Both QTd and QTcd showed significant improvement following successful revascularization of CTO (55.83±14.79 to 38.87±11.69; p<0.001 and 61.02±16.28 to 42.92±13.41; p<0.001). The revascularization of LAD (n=38), Cx (n=28) and RCA (n=73) resulted in decrease in HRV indices, including SDDN, rMSSD, and pNN50, but none of the variables reached statistical significance.
  
  
  CONCLUSIONS
  Successful revascularization of CTO may result in improvement in regional heterogeneity of myocardial repolarization, evidenced as decreased QTcd after the PCI. The revascularization in CTO lesions does not seem to have a significant impact on HRV.
authors: Department of Cardiology, Faculty of Medicine, Bezmialem Foundation University, Istanbul, Turkey.
authors: Ercan
authors: E
authors: Erdogan
authors: Mehmet
authors: M
authors: Akkaya
authors: Ahmet
authors: A
authors: Bacaksız
authors: Abdurrahman
authors: A
authors: Tasal
authors: Osman
authors: O
authors: Sönmez
authors: Emin
authors: E
authors: Asoglu
authors: Seref
authors: S
authors: Kul
authors: Musa
authors: M
authors: Sahın
authors: Murat
authors: M
authors: Turfan
authors: Mehmet Akif
authors: MA
authors: Vatankulu
authors: Omer
authors: O
authors: Göktekin
mesh_terms: D000368:Aged; D002561:Cerebrovascular Disorders / Q000628:therapy*; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009204:Myocardial Revascularization / Q000379:methods*; D062645:Percutaneous Coronary Intervention; D011446:Prospective Studies; D013599:Systole / Q000502:physiology*
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