Relationship between QT Dispersion Changes on Treadmill Test with Coronary Lesion Degree in Patients with Suspected Stable Coronary Artery Disease
Background: QT Dispersion (QTd) is known as a spatial dispersion indicator during myocardial repolarization, and elongation of QTd is related with ventricular arrhythmia event and sudden cardiac death in ischemic heart disease. The increase of QTd happens in coronary heart disease during myocardial ischemia induced by treadmill test. There is no research linking changes of the QTd (?QTd) on exercise test with the severity of coronary lesions in patients with suspected stable coronary artery disease. The aim of this study was to determine the relationship between QTD changes on exercise test with the severity of coronary lesions in patients with stable coronary artery disease and to determine discriminatory value of QTD changes based on the degree of coronary lesions.
Methods: This study was a cross-sectional study in Dr. Sardjito Hospital using data from January 1, 2012. Patients with positive exercise test result, already performed coronary angiography and meet the inclusion and exclusion criteria included in the study. QTd changes during exercise test were measured and Syntax scores were assessed based on the results of coronary angiography. Statistical analysis was performed to determine the relationship between two variables.
Results: There were 76 patients with average of 56.64±7.41 years old, with 54 male subjects (71.1%). The most frequent risk factor were hypertension, there were 57 subjects (75%), followed by 32 subjects of dyslipidemia (42.1%), 27 subjects of DM (35.5%), 24 smoker (31.6%), and 2 subjects with family history of CHD (2.6%). Subjects with high Syntax score were 30 subjects (39.5%) and the low Syntax score were 46 subjects (60.5%). In this research, there was positive relationship with medium strength (r=0.531, p<0.001) between ?QTd and Syntax score. Value of QT dispersion changes of 44.78 milliseconds is optimal cut-off point that discriminates between high and low Syntax score.
Conclusion: There were positive correlations between changes of QTd dispersion with degree of coronary lesion that was analyzed using Syntax with medium strength.
2. Day CP, Mc Comb JM, Campbell RW. QT dispersion: an indication of arrhythmia risk in patients with long QT intervals. Br Heart J. 1990;63:342-4.
3. de Bruyne MC, Hoes AW, Kors JA, et al. QTc dipersion predicts cardiac mortality in the elderly: The Rotterdam study. CirculaPramono
BA dkk: Hubungan antara Perubahan Dispersi QT pada Uji Latih Treadmill
Jurnal Kardiologi Indonesia • Vol. 37, No. 3 • Juli - September 2016 129
4. Zareba W, Moss AJ, Le Cessie S. Dispersion of ventricular repolarization and arrhythmic cardiac death in coronary artery disease. Am J Cardiol. 1994;74:550-3.
5. Psenichnikov I, Tatjana S, Peeter L. Prognostic value of QT interval dispersion during exercise in patients with stable angina. Seminars in Cardiovascular Medicine. 2008;14(3):11-15.
6. Kim BS, Kang JH, Lee SW. Effect of coronary angioplasty on QT and JT dispersion. Korean Circ J. 1998;28:1280-6.
7. Oberman A, Jones WB, Riley CP, et al. Natural history of coronary artery disease. Bull NY Acad Med. 1972;48:1109-1125.
8. Aytemir K, Ozer N, Aksoyek S, et al. QT dispersion plus ST-segment depression: A new predictor of restenosis after succesful percutanesous transluminal coronary angioplasty. Clin Cardiol. 1999;22:409-412.
9. Cheng VY, Berman DS, Rozanski A, et al. Performance of the traditional age, sex, and angina typically-based approach for estimating pretest probability of angiographically significant coronary artery disease in patients undergoing coronary computed tomographic angiography. Results from the multinational coronary CT angiography evaluation for clinical outcomes: an international multicenter registry (CONFIRM). Circulation. 2011;124:2423-2432.
10. Viera AJ, Garret JM. Understanding interobserver agreement: the Kappa statistic. Fam Med. 2005;May,37(5):360-3.
11. Jousilahti P, Vartiainen E, Tuomilehto J, Puska P. Sex, age, cardiovascular risk factors, and coronary heart disease: a prospective follow-up study of 14.786 middle-aged men and women in Finland. Circulation. 1999;99:1165-1172.
12. Rahajeng E, Tuminah S. Prevalensi hipertensi dan determinannya di Indonesia. Maj Kedokt Indon. 2009;Volume:59:580-587.
13. Agustinus R, Yuniadi Y, Setianto B. Correlation between QT dispersion after coronary artery bypass graft and major cardiovascular adverse events. J Kardiol Indones. 2010; 31:72-83.
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).