Which device measures voltage across the body to assess heartbeat?

Which device measures voltage across the body to assess heartbeat?

• A. Stethoscope
• B. Electrocardiogram (EKG)
• C. Sphygmomanometer
• D. Thermometer

Answer: (B)

Heartbeat is driven by electrical signals, and an electrocardiogram captures those electrical voltages as they travel through the heart. By placing electrodes on the skin, the device detects tiny voltage differences and translates them into a waveform over time. This electrical snapshot lets you see the heart's rate and rhythm and identify conduction problems or irregularities. In contrast, a stethoscope listens to the sounds of the heart—the actual beating sounds—rather than measuring electrical activity. A sphygmomanometer measures arterial blood pressure, not electrical signals. A thermometer measures temperature. So the electrocardiogram is the tool that specifically records the voltage changes corresponding to the heart’s electrical activity to assess heartbeat.

Heartbeat is driven by electrical signals, and an electrocardiogram captures those electrical voltages as they travel through the heart. By placing electrodes on the skin, the device detects tiny voltage differences and translates them into a waveform over time. This electrical snapshot lets you see the heart's rate and rhythm and identify conduction problems or irregularities.

In contrast, a stethoscope listens to the sounds of the heart—the actual beating sounds—rather than measuring electrical activity. A sphygmomanometer measures arterial blood pressure, not electrical signals. A thermometer measures temperature. So the electrocardiogram is the tool that specifically records the voltage changes corresponding to the heart’s electrical activity to assess heartbeat.