heildarblóðflæði

Heildarblóðflæði, often translated as total blood flow or cardiac output, refers to the volume of blood pumped by the heart per minute. It is a critical indicator of the cardiovascular system's efficiency and the body's oxygen delivery capacity. This measurement is typically expressed in liters per minute (L/min).

Heildarblóðflæði is determined by two primary factors: heart rate and stroke volume. Heart rate is the number of times the heart beats per minute, while stroke volume is the amount of blood ejected from the left ventricle with each heartbeat. The product of these two values yields the total blood flow. For instance, a resting heart rate of 70 beats per minute and a stroke volume of 70 mL per beat would result in a heildarblóðflæði of 4900 mL/min, or 4.9 L/min.

During periods of increased physical activity or stress, the body's demand for oxygen rises. In response, the heart rate and/or stroke volume increase, leading to a higher heildarblóðflæði to meet these metabolic needs. Conversely, during rest or sleep, heildarblóðflæði decreases. Variations in heildarblóðflæði can be influenced by numerous physiological conditions, including age, fitness level, hydration status, and the presence of certain medical conditions. Clinicians often monitor heildarblóðflæði to assess cardiac function and guide treatment strategies for various cardiovascular diseases.