Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality, and its incidence has grown within several years, quickly becoming the third leading cause of mortality. The disease is characterized by alveolar destruction, air-trapping, and chronic inflammation due to persistent exposure to a large spectrum of harmful particles. The diagnosis of COPD is made by demonstration of persistent and not fully reversible airflow limitation, and different phenotypes may be recognized based on pathophysiological, clinical, and radiological features. However, COPD is a systemic disease with effects involving several organs. For example, mechanical and functional alterations secondary to COPD involve heart function. Indeed, cardiovascular diseases are highly prevalent in patients affected by COPD and represent the primary cause of mortality in such patients. An electrocardiogram is a simple and cheap test that gives much information about the heart status of COPD patients.

Consequently, variations from “normality” can be appreciated in these patients, with the most frequent abnormalities being P-wave, QRS axis, and ventricular repolarization abnormalities, in addition to conduction alterations and a vast number of arrhythmias. As a result, ECG should be routinely performed as a valuable tool to recognize alterations due to COPD (i.e., mechanical and functional) and possible associated heart diseases. This review aims to describe the typical ECG features in most COPD patients and to provide a systematic summary that can be used in clinical practice.