Abstract

Background: Chronic obstructive pulmonary disease (COPD) is associated with increased risk of cardiovascular morbidity and mortality. The aim of this study is to investigate the effect of effort test on corrected QT (QTc) and corrected QT dispersion (QTcd) in patients with newly diagnosed and untreated COPD.
Patients and method: Thirty-three patients who were referred to the chest diseases polyclinic between March- August 2018, who had no previous treatment and had evidence of obstruction in the pulmonary function test were included in the study. As control group, 36 patients who were referred to the cardiology clinic with chest pain, who had no COPD, had an indication for effort test and were negative for effort test, were selected. The study group was initially subjected to pulmonary function test. Patients were then enrolled in the effort test according to the Bruce protocol. QTc and QTcd values were calculated for resting and peak exercise.
Results: The resting QTcd value of the study group was 39.8333 ± 3.6762 ms, value of control group was 38.0244 ± 4.298 ms (p=0.113113, t=1.221961). Peak exercise QTcd values in the study and control groups were 63.356 ± 5.408 ms, 44.475 ± 5.0572 (p<0.00001, t=18.37567), respectively.
Conclusion: There was a statistically significant difference in resting and peak exercise QTcd values in the study group. There was no statistically significant difference between two groups’ resting QTcd values. There was a significant difference between peak exercise QTcd values in the study group and control group.

Keywords: COPD; Corrected QT dispersion; Stress testing