What does an electrocardiogram (ECG or EKG) measure?

An electrocardiogram (ECG or EKG) measures the electrical activity of the heart. This diagnostic tool captures the timing and strength of the electrical signals that trigger each heartbeat. By doing so, it provides critical information about heart rhythm, heart rate, and can reveal the presence of various cardiac conditions such as arrhythmias, ischemia, or other structural heart diseases.

While blood pressure measurements, heart size assessments, and oxygen saturation levels are important aspects of cardiovascular health, they are evaluated through different methods. Blood pressure is measured using a sphygmomanometer, heart size is often assessed via imaging techniques like an echocardiogram or chest X-ray, and oxygen levels are measured using pulse oximetry or arterial blood gas tests. Therefore, the unique role of an ECG focuses specifically on the electrical impulses that enable the heart to function correctly.