Question

The coronary arteries bring blood to the heart muscle and conduction system. They branch off the aorta right next to the aortic valve. Short-term reflexes and long-term physical changes to the heart work to try to maintain normal left ventricular cardiac output (flow) and aortic blood pressure. However, in a person with aortic valve stenosis, there is a risk of compromised (less) blood flow in the coronary arteries. Based on the physical concepts and principles we have talk about in class, describe two (2) reasons that, for a given blood flow, the aortic blood pressure is changed in a person with aortic valve stenosis. Extending from your answer above, briefly describe the reason coronary blood flow could be compromised.

Answer 1

Aortic valve stenosis is the narrowing of the valve of aorta.
When the left ventricle is filled wirh blood from right atrium, the rising pressure in the ventricle causes the aprtic valve to open and pumps the blood into aorta. Once the ventricle becomes empty the pressure in ventricles drop resulting in closure of aortic valve which prevents backflow of blood from aorta.
In aortic valve stenosis, the ventricles have to exert greater pressure in order to pump blood into aorta. This causes ventricular hypertrophy initially. But with time the ventricular wall thins and ventricles become dilated due to continuous overload. This results in impaired ability of left ventricle to pump blood into aorta thus affecting the blood flow to aorta and its branches.