STUDY CLINICAL, RADIOLOGICAL, ELECTROCARDIOGRAPHIC, AND ECHOCARDIOGRAPHIC CHANGES IN CHRONIC CORPULMONALE

Methods: This is a prospective and observational study conducted in 74 included cases admitted in the department of general medicine, NSCB Medical College Hospital, Jabalpur. On the basis of patient’s history, physical findings, radiological findings, and electrographic changes, the diagnosis of chronic cor pulmonale was made and was subjected to echocardiography examination. Results: Cor pulmonale was more common in smokers with male-to-female ratio of 2.52:1 and was more common in the 4 th , 5 th , and 6 th decade of life. ECGshowed 58.10% of cases with RVH, 59.45% with right axis deviation, 48.64% right bundle branch block, and 66.21% with P pulmonale. Echocardiographic evaluation revealed right ventricular dilatation in 100% cases, RVH in 94%, tricuspid regurgitation in 52.70%, right atrial enlargement in 50%, PAH in 97.29%, diastolic septal flattening in 16.21%, paradoxical motion of the IV septum in 8.1%, reduced left ventricular end-diastolic volume in 8.1%, and left ventricular ejection fraction reduced in 22.97%. Conclusion: Detection of chronic cor pulmonale in the early stage is important for therapeutic and prognostic implication. Echocardiography is a non-invasive, affordable investigation for early diagnosis of chronic cor pulmonale


INTRODUCTION
Cor pulmonale is a Latin term that means "pulmonary heart."Cor pulmonale is broadly defined by altered right ventricular (RV) structure and/or function in the context of chronic lung disease and is triggered by the presence of pulmonary hypertension (PAH).Although RV dysfunction is an important sequela of HFpEF and HFrEF, this is not considered as cor pulmonale [1].Cor pulmonale accounts for 5-10% of all heart diseases and 20-30% of all admissions for heart failure.The development of PAH has important prognostic implications, as it significantly increases the risk of hospitalization and is associated with reduced survival [2].The true prevalence of cor pulmonale is difficult to ascertain for two reasons.First, not all patients with chronic lung disease will develop cor pulmonale, and second, our ability to diagnose PAH, and cor pulmonale by routine physical examination and laboratory testing is relatively insensitive [1].Cor pulmonale is estimated to account for 6-7% of all types of adult heart disease in the United States [3], with chronic obstructive pulmonary disease (COPD) due to chronic bronchitis or emphysema the causative factor in more than 50% of cases.Mortality in patients with COPD associated with cor pulmonale is higher than that in patients with COPD alone.Cor pulmonale accounts for 10-30% of decompensated heart failure-related admissions in the United States [4].The common pathophysiologic mechanism behind cor pulmonale is PAH and increased RV afterload sufficient to alter RV structure (i.e., dilation with or without hypertrophy) and function.Normally, mean pulmonary artery pressure (PAP) is only ~15 mmHg and does not increase significantly even with increasing multiples of cardiac output, due to pulmonary vasodilation and blood vessel recruitment in the pulmonary circulatory bed.However, in the setting of parenchymal lung diseases, primary pulmonary vascular disorders, or chronic (alveolar) hypoxia, the circulatory bed undergoes vascular remodeling, vasoconstriction, and destruction.As a result, PAPs and RV afterload increase, setting the stage for cor pulmonale.As the RV is a thin-walled, compliant chamber better suited to handle volume overload than pressure overload, the sustained pressure overload leads to RV dysfunction and failure.Chronic cor pulmonale, however, evolves slowly and in conjunction with modest, compensatory RV hypertrophy (RVH) that lowers wall tension and preserves RV function.First, not all patients with chronic lung disease will develop cor pulmonale, which may be subclinical in compensated individuals.Second, the ability to detect PAH and cor pulmonale by routine physical examination and laboratory testing is relatively insensitive.Echocardiography examination can quantify the extent of RVH and PAH noninvasively.With this regard, our study was designed to study clinical profile, electrocardiographic, radiological changes, and echocardiography in patients with chronic cor pulmonale.

Inclusion criteria
The following criteria were included in the study: • Patients with age >18 years of age • Patients admitted with chronic cor pulmonale were diagnosed on the basis of clinical history, physical examination, radiological, and electrocardiographic findings suggesting chronic cor pulmonale.

Exclusion criteria
The following criteria were excluded from the study: • Patient with primary involvement of the left-sided heart failure

RESULTS
Among the 74 included cases of chronic cor pulmonale, 53 were male and 21 were females.The peak incidence was found in the 4 th , 5 th , and 6 th decades of life.Out of 74 patients, 45 were smokers (Table 1).About 60.81% of the patients in our study had a history of smoking (Table 2).About 100% of cases presented with cough with expectoration and breathlessness, 98.91% with peripheral edema, 62.16% with distension of abdomen, and 81.08% with chest pain.Fever was present in 29.72% of patients whereas loss of appetite was in 94.59%, hemoptysis in 8.1%, and 18% of patients presented with palpitations (Table 3).In the present study, tachypnea was in 100%, accessory muscle usage in 71.62%, pedal edema in 91.98%, rhonchi/

DISCUSSION
Chronic cor pulmonale is a common type of heart disease, as a result of its close association with COPD which has emerged, in recent years, as a leading cause of disability and death [5].There are very few data about the incidence and prevalence of cor pulmonale because the right heart catheterization cannot be performed on a large scale in patients at risk.An alternative approach to diagnose cor pulmonale and to investigate its etiology starts with clinical profile, chest radiography, electrocardiography, and echocardiography.Right heart catheterization is the most accurate but invasive test to confirm the diagnosis of cor pulmonale and gives important information regarding underlying causes [6,7].Two-dimensional (2-D) echocardiography examination demonstrates signs of chronic RV pressure overload which further leads to increased thickness of the RV wall with paradoxical motion of the interventricular septum during systole.With further progression of disease, RVD occurs and the septum shows abnormal diastolic flattening.In advance cases, the septum may bulge into the LV cavity during diastole, resulting in decreased LV diastolic volume and reduction of LV output.Doppler echocardiography is used to assess pulmonary arterial pressure, taking advantage of the functional tricuspid insufficiency that is usually present in PAH.
In our study, 37.83% of the patients belonged to the age group of 51-60 years, 29.72% belonged to >60 years, and 25.6% belonged to 40-50 years.Age distribution was comparable to Padmavathi study's finding that the peak incidence was in the 4 th , 5 th , and 6 th decades of life [8].Similar findings were found by Goswami et al. [9] In Thakker et al. study, out of 60 patients, maximum were from age group of 50-70 years [10].Chronic cor pulmonale was found to be more common in males than females with 53 males (71.62%) and 21 females (28.38%) with a male-to-female ratio of 2.52:1.Goswami et al. [9] found 49 males (61.25%) and 31 females (38.75%) with a male to female ratio of 1.58:1.Males were 83% and 17% Padmavathi [8] and 54% and 46% Thakker et al. [10] Smoking is more prevalent in males as compared to females which may contribute to the development of the disease.About 60.81% of the patients in our study had a history of smoking which closely resembles to Padmavathi study (70%) [8], Cherlopalli and Narahari study (71%) [11], Sankar Rao and Sundar Raj et al. study (76%) [12].In Goswami et al. study, 90% of patients were smokers, Majority being heavy (37.5%)[9].In our study, 100% of cases presented with cough with expectoration and breathlessness, 98.91% with peripheral edema, 62.16% with distension of abdomen, and 81.08% with chest pain.Fever was present in 29.72% of patients whereas loss of appetite was in 94.59%, hemoptysis in 8.1%, and 18% of patients presented with palpitations.Almost similar findings were reported by Sankar Rao and Sundar Raj study [12] and Divya et al. [13].
Left parasternal heave was present in 44.59% of cases in our study, 70% of cases had parasternal heave in the study by Babu et al. [15] Sindhur et al. [16] found loud P2 in 70% of cases, and Padmavathi [8] reported loud P2 in 65% of cases.Murmur of TR was in 48.64% of cases compared to Gireesh et al. [17] study that found 96% of cases had loud P2 and 48% of cases had TR.
In our study among 74 cases, 55% were diagnosed to have chronic bronchitis with or without emphysema, 14.86% had bronchiectasis, 12.16% had bronchial asthma, and 17.56% had emphysema with pulmonary TB.Goswami et al. found that major cause of chronic cor pulmonale was chronic bronchitis with or without emphysema 75% rest were bronchiectasis 10%, fibrosis due to sequelae of pulmonary TB 10%, 1.25% case of interstitial lung disease, and 6.25% were detected to be vertebral anomaly (Kyphoscoliosis), leading to loss of lung volume [9].Padmavathi [8] [9].In Sankar Rao and Sundar Raj study 54% of cases showed evidence of RAD, 48% of cases showed low voltage complexes, and 28% of cases showed P Pulmonale and 20% of cases showed right bundle branch block [12].Thus, ECG despite its limitation can still be useful in diagnosing chronic cor pulmonale.

CONCLUSION
Chronic cor pulmonale is a sequalae of chronic lung disorders with the most common cause being COPD.Diagnosis of cor pulmonale by clinical history, physical examination, chest X-ray, and ECG is often delayed, twodimensional echocardiography is used to measure RV wall thickness and chamber dimensions and Doppler echocardiography can be used to assess PAPs.Despite limitations in the assessment of RV function especially in parenchymal lung disease, echocardiography is found to be useful to diagnose chronic cor pulmonale as it's non-invasive, affordable, and more sensitive than other non-invasive methods.Thus, we would suggest that all patients with chronic lung disease should undergo echocardiographic screening for early detection of cor pulmonale.

Table 7 : ECG changes in chronic cor pulmonale
RVH: Right ventricular hypertrophy, RBBB: Right bundle branch block

Table 4 : Physical examination findings Nagwanshi et al.
Chronic cor pulmonale is common in 4 th , 5 th , and 6 th decade of life.Out of 74 cases 45 (60) had history of smoking.Thirty-nine cases had history of smoking for more than 10 years.About 100% of cases presented with cough with expectoration and breathlessness and 98.91% with peripheral edema.Tachypnea was seen in 100%, accessory muscle usage in 71.62%, pedal edema in 91.98%, rhonchi/crepitations in 94.59%, and cyanosis in 29.7%.The left parasternal heave was seen in 44.59%, loud P2 in 55.40%, and TR (pansystolic murmur) in 48.64% of cases.Most common cause was chronic bronchitis with and without emphysema seen in 55% of cases.Pulmonary TB was seen in 17.56% of cases.
found 50.8% of cases and Vishwanathan et al. 2 found 76.9% cases of chronic bronchitis with or without emphysema as the leading cause of chronic cor pulmonale in their respective studies.Chronic bronchitis was found to be the most common 40% cause for developing cor pulmonale in Thakker et al.

Table 8 : Echocardiographic changes in chronic cor pulmonale
[9]]ry hypertension was seen in 97.29% which is a consistent feature of cor pulmonale and only 2 (2.70%) patients had very early changes of cor-P in which PAH was not seen.In such cases, early diagnosis of cor-P can be made with the help of cardiac catheterization which is invasive modality.Thakker, et al. study had similar findings of right atrial enlargement in 50% of patients and RVH in 80% of patients, various degree of PAH in 96.67% of patients[10].In our study, diastolic septal flattening was seen in 16.21%, paradoxical motion of IV septum in 8.1%, reduced LVEDV in 8.1%, and LVEF reduced in 22.97%.In Sankar Rao and Sundar Raj study, all patients had RV chamber dilatation and mean PAP greater than 25 mm hg and paradoxical interventricular septum motion was observed in 32% of patients[12].In Goswami et al. study showed enlarged right atrium and right ventricle with pulmonary artery hypertension either associated with trivial or moderate TR in 100% of cases[9].In Divya et al. study, PAH, present in 100% cases, also enlarged right atrium, right ventricle, and RVH with pulmonary artery hypertension either associated with trivial or moderate TR in every patient while the left ventricular dysfunction is present in 23% of cases