Which technology most accurately measures heart chambers for position and size?

• A. Heart rate monitor
• B. ECG (or EKG)
• C. Metabolic cart
• D. Stopwatch

Answer: (B)

Understanding how the heart’s structure is assessed relies on imaging that shows the actual size and position of the chambers. An electrocardiogram records the heart’s electrical activity and, while it doesn’t measure chamber size directly, it can reveal signs of chamber enlargement or hypertrophy through specific patterns. The other options measure things unrelated to anatomy: a heart rate monitor tracks pulse rate, a metabolic cart analyzes gas exchange and energy use, and a stopwatch measures time. Because ECG is the tool that provides information tied to how the heart's chambers are functioning and can hint at structural changes, it’s the best choice among these options for information related to heart chambers.