What is the primary purpose of an electrocardiogram (ECG)?

The primary purpose of an electrocardiogram (ECG) is to understand the electrical conduction pattern in heart muscles. An ECG provides a visual representation of the heart's electrical activity over time, allowing healthcare professionals to identify the rhythm of the heart and detect any abnormalities or issues with the heart's electrical system. This information is crucial for diagnosing various heart conditions, such as arrhythmias, myocardial infarctions, and other forms of heart disease.

Monitoring blood pressure changes is a different procedure that focuses on the vascular system rather than the electrical activity of the heart. Assessing lung capacity requires pulmonary function tests, which measure how well the lungs are working, whereas measuring glucose levels in the blood involves blood tests that specifically evaluate metabolic processes, unrelated to the heart's electrical activity. Thus, the correct choice emphasizes the integral role of ECGs in cardiovascular health.