Stroke volume is typically measured in which units?

Stroke volume is typically measured in which units?

• A. ml/beat
• B. L/min
• C. ml/min
• D. L/beat

Answer: (A)

Stroke volume is the amount of blood the ventricle ejects with each heartbeat, so its units reflect a volume per beat. That makes milliliters per beat the standard way to express it, since a typical healthy SV is around 60–100 mL per beat. Using other units shifts the meaning: liters per minute or milliliters per minute describe how much blood moves each minute (cardiac output, which equals SV × heart rate); liters per beat would be the same idea as ml per beat but in a larger unit, which isn’t the common convention. Thus ml/beat is the most appropriate and widely used unit for stroke volume.

Stroke volume is the amount of blood the ventricle ejects with each heartbeat, so its units reflect a volume per beat. That makes milliliters per beat the standard way to express it, since a typical healthy SV is around 60–100 mL per beat. Using other units shifts the meaning: liters per minute or milliliters per minute describe how much blood moves each minute (cardiac output, which equals SV × heart rate); liters per beat would be the same idea as ml per beat but in a larger unit, which isn’t the common convention. Thus ml/beat is the most appropriate and widely used unit for stroke volume.