Final answer:
Aortic and mitral valve stenosis characteristics include valve rigidity and potential calcification, leading to compromised heart function that may require surgical intervention, especially if associated structures like chordae tendineae are damaged.
Step-by-step explanation:
The characteristics of aortic valve stenosis and mitral valve stenosis involve the heart valves becoming rigid and potentially calcifying over time, leading to a reduced flexibility that can impede normal blood flow. For the aortic valve, stenosis is common in older populations, affecting about 2 percent of people over 65 years and rising to approximately 4 percent of individuals over 85 years. When dealing with stenosis, the heart must work harder to pump blood through the narrowed valve, which can ultimately weaken the heart muscle. The mitral valve, also known as the atrioventricular valve, could get compromised if the chordae tendineae tear or if the papillary muscle dies, such as during a myocardial infarction. Compared to semilunar valves like the aortic and pulmonary valves, which don't have chordae tendineae and papillary muscles, the mitral valve depends on them for proper function to prevent backflow. If these structures are damaged, it can lead to severe insufficiency and rapid deterioration of the patient’s condition, necessitating immediate surgical attention.