Which term describes the measure of cardiac activity usually expressed as beats per minute?

Which term describes the measure of cardiac activity usually expressed as beats per minute?

• A. Heart Rate
• B. Stroke Volume
• C. Cardiac Output
• D. Mean Arterial Pressure

Answer: (A)

Heart rate is the number of times the heart contracts in one minute, making it the direct measure of cardiac activity expressed in beats per minute. This is exactly what the prompt is asking for. Stroke volume, by contrast, is the amount of blood ejected with each beat, not how often the heart beats. Cardiac output combines both rate and volume (it's the product of heart rate and stroke volume), so it reflects total blood flow per minute but not the beat count itself. Mean arterial pressure is an average arterial pressure influenced by cardiac output and vascular resistance, not a direct measure of how fast the heart is beating. In clinical terms, resting heart rate typically ranges from about 60 to 100 beats per minute, with higher or lower values indicating changes in pacing but not the measurement of activity itself.