How is cardiac output calculated?

Cardiac output is a crucial measurement in understanding the heart's efficiency and overall circulatory function. It is defined as the volume of blood the heart pumps per minute. To calculate cardiac output, the formula involves two key components: stroke volume and heart rate.

Stroke volume refers to the amount of blood ejected by the left ventricle with each heartbeat, while heart rate indicates how many times the heart beats in one minute. Therefore, multiplying the stroke volume by the heart rate gives the total volume of blood pumped by the heart in one minute, effectively providing the cardiac output.

This relationship is significant because both stroke volume and heart rate can individually impact overall cardiac performance. A higher stroke volume or a higher heart rate can increase cardiac output, which is vital in situations such as exercise or when the body needs increased blood flow.

Other options, while relevant to cardiac function, do not accurately define how cardiac output is calculated. For instance, some include terms that describe different aspects of cardiovascular physiology but do not correctly address the direct calculation of cardiac output. This understanding is essential in clinical settings, especially for paramedics managing patients with cardiac issues.