Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality across the globe. According to World Health Organization estimates, 65 million people have moderate to severe COPD. More than 3 million people died of COPD in 2005 corresponding to 5% of all deaths globally and it is estimated to be the third leading cause of death by 2030. Smoking is by far recognized to be the most important risk factor for development of COPD. Apart from its respiratory morbidity and mortality, its cardiovascular effects are concerning. Timely diagnosis of COPD and early recognition of any cardiovascular complications of COPD is the key to success. In our study we will demonstrate the various ECG changes in COPD patients and their relationship with severity of the disease.