Determinination of the Frequency of Altered Cardiac Repolarization by Measuring the Heart rate Corrected QT Interval in COPD Patients
Shahla Roshan Memon
Liaquat University of Medical and Health Sciences, Jamshoro, Pakistan.
Muhammad Aslam Rind *
Liaquat University of Medical and Health Sciences, Jamshoro, Pakistan.
Maria Nazir
PUMHS, Nawabshah, Pakistan.
Shah Jehan Memon
PUMHS, Nawabshah, Pakistan.
Muhammad Saleem Rind
PUMHS, Nawabshah, Pakistan.
*Author to whom correspondence should be addressed.
Abstract
Objectives: To determine the frequency of altered cardiac repolarization by measuring the heart rate corrected QT interval in COPD patients.
Setting: Department of Medicine at LUMHS hospital Hyderabad/Jamshoro.
Study Design: Descriptive Cross sectional study.
Duration of Study: 6 months from 01-03-2019 to 31-08-2019.
Methods: A total of 232 patients with severe acute exacerbation of COPD were included in this study. A 12 lead ECG was performed. QT intervals were measured on a resting ECG tracing in lead II. The QT interval was measured manually from the starting point of the QRS complex to the terminal point of the down slope of the T wave.
Results: A total of 232 patients with COPD were included in this study. Most of the cases were above 50 years of age. The average age of the patients was 53.74±4.35 years. There were 92.67% (215/232) male and 7.33% (17/232) female. Out of 232 patients, 21.14% were current smoker and 75.86% were ex-smoker. A QTc interval >0.44 seconds was considered abnormally prolonged. Frequency of altered cardiac repolarization by measuring the heart rate corrected QT interval in COPD patients was 31.47% (73/232). Rate of altered cardiac repolarization was not significant among different age groups (p=0.641). Rate of altered cardiac repolarization was significantly high in male as compare to female (33.5% vs. 5.9%; p=0.018). This was not significant between obese and non-obese groups (p=0.100). Rate of altered cardiac repolarization was significantly high in former smoker (p=0.0005) and those patients whose duration of COPD was above 15 years (p=0.0005).
Conclusion: Patients with hypoxic chronic obstructive pulmonary disease (COPD) have evidence of a subclinical parasympathetic autonomic neuropathy, with apparent preservation of sympathetic function. Measuring heart rate corrected QT interval (QTc) test is repeatable, easy to perform and a sensitive indicator for autonomic dysfunction in breathlessness individuals with COPD.
Keywords: Chronic obstructive pulmonary disease, QT interval, Altered cardiac repolarization