What does the electrocardiogram measure?

The electrocardiogram (EKG or ECG) measures the heart's electrical activity. It captures the electrical impulses that initiate and regulate each heartbeat. These impulses help assess the heart's rhythm, electrical conduction, and overall function. By placing electrodes on the skin, the EKG records the electrical waves as they move through the heart, which is crucial for diagnosing various cardiac conditions, such as arrhythmias, ischemia, and other heart diseases. This information is vital for healthcare providers to determine the appropriate treatment or management for cardiac issues.

In contrast, heart rate variability involves the changes in time intervals between heartbeats, which is a different measurement that reflects autonomic nervous system function. Blood pressure fluctuations pertain to the force of blood against the artery walls, while cardiac output efficiency refers to the effectiveness of the heart in pumping blood. These measurements are important but do not directly involve the electrical activity of the heart that the EKG specifically monitors.