Effect of coronary artery bypass on QT dispersion M.


Marzieh Nikparvar 1 , * , Shahdad Khosro Panah 2 , Mohammad Hassan Nemati 3 , Hossein Farshidi 1

1 Assistant Professor, Department of Internal Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran.

2 Associate Professor Department of Internal Medicine, Shiraz University of Medical Sciences, shiraz, Iran.

3 Assistant Professor, Department of Surgery, Shiraz University of Medical Sciences, Shiraz, Iran.

How to Cite: Nikparvar M, Khosro Panah S, Nemati M H, Farshidi H. Effect of coronary artery bypass on QT dispersion M., Hormozgan Med J. 2006 ; 10(2):e89798.


Hormozgan Medical Journal: 10 (2); e89798
Published Online: November 20, 2006
Article Type: Research Article
Received: February 02, 2005
Accepted: November 20, 2006




Introduction: QT dispersion (QT Max – QT min) reflects inhomogeneous
ventricular depolarization that may provide a substrate for serious arrythmias and
is associated with adverse clinical outcomes in patients with coronary artery
disease. Some studies have shown reduction in QT dispersion after successful
angioplasty due to coronary reperfusion, but effect of coronary artery bypass
grafting on QTd is less known. This study evaluated the effects of coronary
artery bypass grafting (CABG) on QT dispersion in first days after surgery.
Methods: In this descriptive cross-sectional study, QTd of 50 patients who
underwent coronary artery bypass grafting were calculated pre-and post-surgery
This measurement was performed after surgery on three occasions (first day,
third day and predischarge) in patients without serious or malignant arrythmias.
Results: QTd & QTcd (mean SD) decreased in third postoperative day compared
to preoperation values. QTd and QTcd decreased from 62.9 (26.9), and 64.8
(28.08) to 43.1 (22.8) and 59.4 (29.9) respectively (P<0.005 and P<0.03) in
the third day after surgery comparing to presurgery. The decrements was more
significant between predischarge and preoperation: QTd decreased from
62.2(26.9) to 41.6(24.16) and QTcd decreased from 71.7(32.47) to 51.5(27.69)
Conclusion: CABG, the most comprehensive method of revascularization in
patients with coronary artery disease, is an important factor in reducing QT
dispersion and eventually reducing malignat ventricular arrhythmia after surgery.


Coronary Disease – Coronary Artery Bypass – Electrocardiography

© 2006, Hormozgan Medical Journal. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.



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