An electrocardiogram is best described as a test that records what?

• A. Kidney function
• B. The electrical activity of the heart
• C. Blood pressure
• D. Respiratory rate

Answer: (B)

An electrocardiogram records the heart’s electrical activity. The heart’s rhythm is driven by electrical impulses that trigger the atria and ventricles to contract, and skin electrodes pick up these signals and display them as a tracing. This shows heart rate, rhythm, and conduction patterns, helping detect abnormalities like arrhythmias or ischemia. It doesn’t measure kidney function, blood pressure, or respiratory rate, which require different tests or measurements.