How is cardiac output calculated?

Cardiac output is defined as the amount of blood the heart pumps in one minute and is a critical measure of cardiovascular efficiency. The correct method to calculate cardiac output involves multiplying heart rate by stroke volume.

Heart rate refers to the number of times the heart beats per minute, while stroke volume is the amount of blood pumped by the heart with each beat. Therefore, by multiplying these two values together—heart rate (beats per minute) and stroke volume (milliliters per beat)—you get the total volume of blood ejected by the heart in one minute, which is expressed in liters per minute.

This calculation is essential for understanding how effectively the heart is delivering oxygen and nutrients to tissues throughout the body, particularly during exercise or in response to different physiological demands.

Other choices involve concepts that do not directly yield cardiac output. For instance, stroke volume divided by heart rate does not reflect the total volume pumped per minute. Stroke volume plus blood pressure mixes different types of measurements and does not produce a meaningful physiological value. Similarly, heart rate plus oxygen consumption does not provide a measure of blood flow, making it irrelevant for calculating cardiac output.