European Journal of Cardiovascular Medicine

Chronic obstructive pulmonary disease (COPD) is a name coined for the diseases that were previously known as chronic bronchitis and emphysema. The British Medical Research Council (BMRC) defined chronic bronchitis as “daily productive cough for at least three consecutive months for more than two successive years.1American Thoracic Society (ATS) in 1962 defined emphysema as an “anatomic alteration of the lung characterized by an abnormal enlargement of the air spaces distal to the terminal, non-respiratory bronchiole, accompanied by destructive changes of the alveolar walls”.2The definition of emphysema put forth by the National Heart, Lung and Blood Institute in 1984 is as “a condition of the lung characterized by abnormal, permanent enlargement of airspaces distal to the terminal bronchiole, accompanied by the destruction of their walls, and without obvious fibrosis”.3 Reid reported that “the diagnosis of emphysema by itself is incomplete unless it is taken into account the presence or absence of chronic bronchitis and vice versa”.4McDonough et al5 have recently reported extensive obliteration of terminal bronchioles in patients with COPD who have emphysema, suggesting that “the permanent enlargement of the distal airspaces may serve only as a structural biomarker, being a secondary result of small airway inflammation and destruction”.6 Thus, COPD has both airway (central and small airways) and airspace abnormalities. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) recently defined COPD as “a common preventable and treatable disease characterized by persistent airflow limitation that is usually progressive and associated with an enhanced chronic inflammatory response in the airways and the lung to noxious particles or gases. Exacerbations and co-morbidities contribute to the overall severity in individual patient”.7 COPD is predicted to be the third leading cause of death worldwide by 2020.8 According to studies, India has 17 million people living with chronic obstructive pulmonary disease, a number that is expected to rise to 22 million by 2016.9 Recent studies have reported that an emphysematous lung was associated with acute exacerbation of COPD and co-morbidities including atherosclerosis and osteoporosis10-12 . There are no specific features on plain chest-X-ray for chronic bronchitis. The features usually described are for emphysema. Bronchial wall thickening seen as parallel line opacities on plain chest X-ray has been described in chronic bronchitis.

However, whether the severity of emphysema, as designated by the emphysema index on computed tomography (CT) scans, is a parameter associated with severe respiratory symptoms and prognosis, or is independent to airflow limitation, remains unclear. Moreover, although high-resolution CT (HRCT) accurately assesses the degree of emphysema, measuring the emphysema score is still not routinely performed in clinical practice. Patients who have airflow obstruction, decreased diffusing capacity of the lung for carbon monoxide (DLCO) suggests emphysema 13 and DLCO correlate well with the degree of emphysema, as assessed by HRCT.14,15 Measuring DLCO is feasible in clinical practice, and there is no radiation exposure (in contrast to HRCT). COPD is associated with significant extra pulmonary (systemic) effects among which cardiac manifestations are most common. Cardiovascular disease accounts for approximately 50% of all hospitalization and nearly one third of all deaths, if forced expiratory volume in one second (FEV1)> 50% of predicted.16In more advanced disease cardiovascular disease account for 20%–25% of all deaths in COPD.17 COPD affects pulmonary blood vessels, right ventricle, as well as left ventricle leading to development of pulmonary hypertension, corpulmonale, right ventricular dysfunction, and left ventricular dysfunction too. Echocardiography provides a rapid, non invasive portable and accurate method to evaluate the right ventricle function, right ventricular filling pressure, tricuspid regurgitation, left ventricular function and valvular function.18 Many studies have confirmed that echocardiographically derived estimates of pulmonary arterial pressure co-relate closely with pressures measured by right heart catheter. 19, 20

Arterial blood gas analysis provides the best clues as to acuteness and severity. In general, renal compensation occurs even in chronic CO2 retainers; thus, pH usually is near normal.

Generally, consider any pH below 7.3 a sign of acute respiratory compromise serum chemistry. These patients tend to retain sodium. Diuretics, beta-adrenergic agonists, and theophylline act to lower potassium levels; thus, serum potassium should be monitored carefully. Beta-adrenergic agonists also increase renal excretion of serum calcium and magnesium, which may be important in the presence of hypokalemia.

In addition, studies of ECG characteristics in COPD patients focus on ECG abnormalities related to pulmonary hypertension and cor pulmonale, i.e. right atrial enlargement, right ventricular hypertrophy, P-pulmonale, right axis deviation and right bundle branch block, while less than 1% of the COPD patients develop pulmonary hypertension.21 Electrocardiography is the standard method for diagnosing cardiac arrhythmias.22 In addition, it can provide useful information about cardiac disease or end-organ damage, e.g., detection of prior myocardial infarction, ischemia, chamber enlargements, conduction abnormalities, left ventricular hypertrophy, etc., and it is helpful for indicating which additional cardiac investigations should be considered.22 The present study was undertaken to evaluate clinico-radiological, spirometry, diffusion capacity, ECG, echocardiographic and biochemical parameters in chronic obstructive pulmonary disease.

Study setting: The study conducted in the department of Pulmonary Medicine, Kamineni Institute of Medical Sciences, Sreepuram, Narketpally.

Study Population: All COPD patients attending OPD and inpatient admissions in Pulmonology Department.

Study subjects: Inclusion criteria:1. Patients diagnosed to have COPD as per GOLD criteria.2. Patients between 35 to 80 years. 3. Both male and female patients. 4. Patients with h/o Smoking (current smokers and quitters of smoking) and biomass exposure.

EXCLUSION CRITERIA: 1.Patients with HTN, DM, Ischemic heart disease, severe anemia, renal and liver disease. 2. Patients who are Critically ill, unable to perform spirometry, pulmonary tuberculosis, lung malignancies, bronchiectasis and patients with bronchial asthma.

Period of study: October 2015 - September 2017.

Study design:  Cross- sectional study.

Sample size: minimum sample estimated is around 100.

Study Tools: Pre structured questionnaire, Chest X-ray, ECG machine, 2D Echo machine, Spirometer, ABG machine, DL_CO machine.

Ethical Considerations: Institutional ethics Committee approval was obtained. Written and informed consent taken from all the patients.

Procedure: A pretested predesigned proforma was prepared after applying the above inclusion and exclusion criteria, meeting the objectives of study for the present study 100 patients were selected and they were subjected to the following examinations.

1. History and Physical Examination: In every case a detailed history was elicited and thorough clinical examination was done as indicated in the proforma.
2. Radiographic examination: Chest X-ray postero-anterior view and left lateral view were obtained to detect signs chronic bronchitis and emphysema.
3. Spirometry: Spirometry was done on computerized spirometer. Spirometery was performed pre and post bronchodilator when the patients were clinically stable. Test was performed with the patient comfortably seated, with clothes loosened. The patient was instructed to take a deep inspiration then close the lips around the mouth piece and blows out as hard and fast as possible, followed by deep inspiration. Volume was obtained on the vertical axis of recording paper and time on the horizontal axis. The curve which was obtained is referred to as forced vital capacity curve. Forced Vital Capacity (FVC) is the volume of air that can be forcibly exhaled (as fast as possible) after a maximal inspiration. It is expressed in liters.

Forced expiratory volume in one second (FEV1) It is defined as the volume of air expelled in the first second, from the start of maximum expiratory effort of the forced vital capacity. It is expressed in liters or percentage of predicted value. Gold’s criteria is taken into consideration after post bronchodilator to check the level of obstruction. 4. DIFFUSING CAPACITY: DL_CO was done on DL_CO Machine. DL_CO was performed when the patients were clinically stable. Test was performed with the patient comfortably seated, with clothes loosened.

Techniques for estimating DL_CO - 1. Steady-state, 2. Re breathing and 3. Single-breath methods: we followed this technique for estimating DL_CO 

Single-breath (SB) method: 1. The subject exhales to residual volume and then inhales to maximal breath a gas mixture containing a very low concentration of carbon monoxide plus an inert gas, usually helium. 2. After a maximal inhalation to total lung capacity (TLC), the subject holds his or her breath for 10 seconds and then exhales completely. 3. After sufficient expiration to clear the dead space, a gas sample is collected to estimate final alveolar CO and helium fractions and analyzed. 4. By measuring the concentration of the exhaled carbon monoxide and helium, the value of the DL_CO can be computed. We tool DLco adj(adjusted) in this study. 5. After inspiration, the alveolar partial pressure of CO falls exponentially as CO enters the capillary blood. 6. The volume of CO absorbed in the lungs can be calculated from the alveolar volume and the initial and final concentrations of CO in alveolar gas.  7. The rate of CO uptake during the breath-hold is a function of the alveolar PACO, which falls exponentially during the breath-hold. Capillary CO pressure is assumed to be equal to zero. 4.

ECHOCARDIOGRAPHY: 2D-echo was assed using 2D-echo machine and looked in for any right ventricular dilation and pulmonary artery hypertension.

5. ECG: ECG was assed using ECG machine and looked in for "p" wave amplitude, QRS axis, R/S in V1 and “R” wave progression.

Statistical analysis: Data entry was done using M.S. Excel and it was statistically analysed using Statistical package for social sciences (SPSS Version 16) for M.S.Windows. Descriptive statistical analysis was carried out to explore the distribution of several categorical and quantitative variables. Categorical variables were summarized with n (%), while quantitative variables were summarized by mean±S.D. All results were also presented in tabular form and are also shown graphically using bar diagram or pie diagram as appropriate.  Inferential Statistics: The difference in the two groups were tested for Statistical Significance using by chi square test.  P-value less than 0.05 considered to be statistically significant.

The maximum number of study subjects were among the age group 61 to 70 years constituting 44% and minimum being 41to 50 years constituting 12%.Among the study subjects maximum age 79 years and the minimum age 41 years. The mean age of the patients was 62 ± 9.54 years. It was observed from the table-1 that the majority of the study subjects were being males which constitute 76% of the total study population and minimum being females which constitute 24 % of the study population. 68% of the study population belong farmers, 20 % house wives and the least being business men. it can be observed that all the patients had more than 20 smoking pack years and majority were in 30-50 pack year exposure duration. Biomass exposure is present in 20% of the study population.

Table no-1: Baseline Parameters (n=100)

Majority of people in the present study group belonged to more than 5 years duration of illness. All the patients presented with cough and expectoration. Breathlessness and wheezing was present in majority of the patients and fever was present among small percentage of 20% patients. Cyanosis found in 16%patients, flapping tremor being 4%, pursed lip breathing and inter costal in drawing being 12 % respectively. In present study about 88% of patients showed ronchi/crepitations and only 32% showed barrel shaped chest. Decreased Chest movements observed among 64% and Decreased Breath sounds observed 72%. (Table-2)

Table-2: COPD feature

In our study 60 patients showed emphysematous changes on chest x-ray and 48 patients showed increased bronchovascular markings (BV markings). 8 patients showed cardiomegaly and 8 patients with PAH. Majority of patients which is 84% had decrease in FEV1% which is below the predicted value of 50%. 88% of the study population has DL_CO values normal and only 12 % of the study population have DL_CO less than 80% of the predicted. ECG studies showed that “P” wave amplitude  > 2.5 mm seen in 36.7 % of the patients ,20% of the patients had QRS axis > 90, R/S in V5 <1 in 16.7 % of patients and Poor “R” wave progression in 26.7% of the patients. Out of 100 patients, 20 patients showed respiratory acidosis which constitutes 20% of total study population. Echocardiography shows 92% of patients with normal findings and 8% with Right ventricular dilation with pulmonary hypertension.  (Table-3)

Table-3: Radiological, Spirometric, Electrocardiographic, Blood Gas, and Echocardiographic Findings in COPD Patients.

Among all COPD patients who ever had Fev1% <30%, all having DL_CO <80% Predicted. This was found statistically significant. Majority (62.5%) had acidosis that ever had Fev1% <30% and this was found spastically significant. Majority COPD patients (25%) had RVD N PHTN, when their Fev1% is <30%. And this was statistically significant. (P<0.05)

DLCO is a valuable adjunct to spirometry in assessing COPD severity, reflecting not only alveolar-capillary damage but also correlating strongly with advanced disease features such as severe airflow obstruction, respiratory acidosis, and right ventricular dysfunction. Its inclusion in routine evaluation enhances clinical assessment, aids in identifying emphysematous phenotypes, and provides insight into cardiopulmonary involvement and overall disease burden

Financial support and sponsorship:

Nil

Conflicts of interest:

There are no conflicts of interest

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