A COMPARATIVE STUDY OF PRE AND POST TREATMENT ECHOCARDIOGRAPHIC FINDINGS IN ACUTE EXACERBATION OF COPD PATIENTS, Tahir Ashraf Kar, Syed Mudasir Qadri, Umar Hafiz Khan, Imran Hafeez, Anjum Afshan, Aamir Shafi, INTERNATIONAL JOURNAL OF PURE MEDICAL RESEARCH : Volume-7 | Issue-9 | September-2022