What aspect of cardiac output is affected by aging?

The decline in cardiac output with aging is attributed to several physiological changes that occur within the heart and the cardiovascular system. As individuals age, there is often a decrease in the efficiency of the heart's pumping ability due to factors such as ventricular hypertrophy, stiffening of the arterial walls, and reduction in the heart's maximum heart rate. These changes can lead to a lower stroke volume and a decreased ability of the heart to respond to increased demands during physical activity.

Specifically, the relationship between the aging heart and cardiac output reveals that younger hearts can typically increase output significantly to meet the body's demands during exercise or stress, but this adaptability diminishes with age. Additionally, age-related alterations in cardiac conduction and an increased prevalence of cardiovascular diseases can further impair cardiac function. Consequently, this overall reduction in the heart's efficiency and output capacity is why a decline in cardiac output is commonly observed in older adults.