Contributors of the Severity of Airflow Limitation in COPD Patients / 결핵및호흡기질환

BACKGROUND: Although airway obstruction in chronic obstructive pulmonary disease (COPD) is due to pathologic processes in both the airways and the lung parenchyma, the contribution of these processes, as well as other factors, have not yet been evaluated quantitatively. We therefore quantitatively evaluated the factors contributing to airflow limitation in patients with COPD. METHODS: The 213 COPD patients were aged >45 years, had smoked >10 pack-years of cigarettes, and had a post-bronchodilator forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) <0.7. All patients were evaluated by medical interviews, physical examination, spirometry, bronchodilator reversibility tests, lung volume, and 6-minute walk tests. In addition, volumetric computed tomography (CT) was performed to evaluate airway wall thickness, emphysema severity, and mean lung density ratio at full expiration and inspiration. Multiple linear regression analysis was performed to identify the variables independently associated with FEV1 - the index of the severity of airflow limitation. RESULTS: Multiple linear regression analysis showed that CT measurements of mean lung density ratio (standardized coefficient beta=-0.46; p<0.001), emphysema severity (volume fraction of the lung less than -950 HU at full inspiration; beta=-0.24; p<0.001), and airway wall thickness (mean wall area %; beta=-0.19, p=0.001), as well as current smoking status (beta=-0.14; p=0.009) were independent contributors to FEV1. CONCLUSION: Mean lung density ratio, emphysema severity, and airway wall thickness evaluated by volumetric CT and smoking status could independently contribute to the severity of airflow limitation in patients with COPD.

The Relationship Between Chronic Atrial Fibrillation and Reduced Pulmonary Function in Cases of Preserved Left Ventricular Systolic Function

BACKGROUND AND OBJECTIVES: The purpose of this study was to investigate the relationship between chronic atrial fibrillation (AF) and reduced pulmonary function. SUBJECTS AND METHODS: Eighty-six chronic AF patients who were enrolled from annual health examination programs were studied using echocardiography and pulmonary function tests (PFT). Echocardiography and PFT matched for age, gender, and year performed were selected by the control group who had normal sinus rhythms. Patients with ejection fractions <50%, valvular heart disease, or ischemic heart disease were excluded. RESULTS: In the chronic AF patients, the forced expiratory volume at one second (FEV1), FEV1%, and FEV1/forced vital capacity (FVC) were significantly reduced, and the right ventricular systolic pressure was significantly increased. Episodes of heart failure were more frequently associated with the chronic AF patients than the controls. In particular, the FEV1% had the most meaningful relationship to chronic AF after an adjustment for cardiovascular risk factors {p=0.003, Exp (B)=0.978, 95% confidence interval (CI):0.963-0.993}. CONCLUSION: Reduced FEV1%, which represents the severity of airway obstruction, was associated with chronic AF, and the greater the pulmonary function impairment, the greater the co-existence with AF and congestive heart failure in those with preserved left ventricular systolic function.