Which test is primarily used to measure the electrical activity of the heart?

• A. Echocardiogram
• B. Stress test
• C. Electrocardiogram
• D. Cardiac catheterization

Answer: (C)

The electrocardiogram (ECG or EKG) is a test specifically designed to measure the electrical activity of the heart. It records the electrical impulses that trigger each heartbeat, providing a graphical representation of the heart's rhythm and the time it takes for electrical impulses to travel through the heart. This information is crucial for identifying various cardiac conditions, such as arrhythmias, heart attacks, and other heart-related issues.

In contrast, an echocardiogram employs ultrasound waves to create images of the heart's structure and assess its function, rather than measuring electrical activity. A stress test evaluates how the heart responds to physical exertion and can provide insights into its performance during increased activity. Cardiac catheterization involves invasive procedures to examine the coronary arteries and heart chambers, focusing primarily on blood flow and pressure rather than electrical activity.

This distinction highlights why the electrocardiogram is the appropriate choice for measuring the heart's electrical function.