What does an electrocardiogram assess?

An electrocardiogram (ECG or EKG) is a diagnostic tool used to assess the heart's electrical activity. It records the electrical impulses that trigger each heartbeat, providing information about the rhythm, rate, and overall electrical activity of the heart. By placing electrodes on the skin, the ECG captures the electrical signals that govern heart function, allowing healthcare providers to detect abnormalities such as arrhythmias, heart attacks, and other conditions that affect the heart's electrical system.

The other options address different aspects of cardiovascular assessment. For example, the physical structure of the heart is typically assessed using imaging techniques such as echocardiograms or MRIs rather than an ECG. Coronary artery blockages can be indicated by an ECG but are more definitively diagnosed through imaging studies such as angiograms. Blood flow through the heart is not directly measured by an ECG; instead, it can be evaluated through other tests or imaging studies, which examine how blood circulates through the heart chambers and vessels.