What is the effect of immobility on the cardiovascular system?

• A. Increased cardiac workload and risk of orthostatic hypotension.
• B. Decreased heart rate.
• C. No effect
• D. Improved cardiac output

Answer: (A)

Immobility disrupts normal blood flow by letting blood pool in the legs and abdomen because the muscle pump isn’t helping push blood back to the heart. This reduces venous return to the heart, so the body compensates by increasing sympathetic drive to maintain blood pressure. The heart works harder (increasing rate and contractility) to maintain cardiac output, which raises the overall cardiac workload. When a person does stand, the already lowered venous return can’t be quickly restored, leading to orthostatic hypotension. So the main effects are a higher workload for the heart and a greater risk of blood pressure drop upon standing. The other options don’t fit: a slower heart rate isn’t typical with immobility, and there is a real impact on the cardiovascular system rather than no effect, with cardiac output not being improved by immobility.