Cardiology>>>>>Cardiac Rehabilitation
Question 19#

You are working on a cardiology ward in a district general hospital and have been asked to teach the medical students about cardiac rehabilitation. A particularly keen student asks about the physiological mechanisms for the cardiac benefits of exercise. 

Which one of the following statements is incorrect?

A) On a microvascular level there is improved endothelium-dependent vasodilation, with decreased expression and activity of endothelial NO synthase
B) Exercise causes changes in the autonomic nervous system which reduce the resting sympathicoadrenergic tone
C) In patients with heart failure, as well as the benefits of exercise training already listed, studies have shown a reduction in circulating levels of angiotensin II, aldosterone, and atrial natriuretic peptide
D) Exercise induces modifications within the renin–angiotensin–aldosterone system which result in reduced plasma renin activity
E) Patients with chronic heart failure benefit from better respiratory function and improved skeletal muscle metabolism and function

Correct Answer is A

Comment:

There is increased expression of NO synthase.

Exercise training has several neurohormonal effects. Changes in the autonomic nervous system reduce the resting sympathicoadrenergic tone, and modifications within the renin–angiotensin– aldosterone system result in reduced plasma renin activity. On a microvascular level there is improved endothelium-dependent vasodilation, with increased expression and activity of endothelial NO synthase, as well as increased angiogenesis and collateralization. In patients with heart failure, as well as the benefits of exercise training listed in the question, studies have shown a reduction in circulating levels of angiotensin II, aldosterone, and atrial natriuretic peptide. These patients also benefit from better respiratory function and improved skeletal muscle metabolism and function.