Valvular Hear Disease - Short Questions

 Regarding Valvular Hear Disease answer the following questions:

1. What is the difference between valvular insufficiency and valvular regurgitation?
2. What types of myocardial hypertrophy can result from valvularabnormalities?
3. What is the most serious long-term consequence of either concentric or eccentric hypertrophy?
4. What is the relationship between the pressure gradient across a stenotic valve, the blood flow across the valve, and the valve area?

Answers:
1. What is the difference between valvular insufficiency and valvular regurgitation?
Regurgitation and insufficiency are interchangeable terms to describe backward flow of blood across a valve at a time in the cardiac cycle when there would be no significant flow across a competent valve.

2. What types of myocardial hypertrophy can result from valvular abnormalities?
When there is a pressure load imposed on the ventricle (such as aortic stenosis for the left ventricle or pulmonic stenosis for the right ventricle), concentric hypertrophy develops. Concentric hypertrophy means that the myocardial wall thickness is increased w ith a normal or decreased internal ventricular diameter. A volume load (such as aortic insufficiency or mitral regurgitation for the left ventricle or tricuspid regurgitation for the right ventricle) results in eccentric hypertrophy; the wall thickness is normal but the internal diameter of the ventricle is increased. Overall, left ventricular mass is increased in both types of hypertrophy.


3. What is the most serious long-term consequence of either concentric or eccentric hypertrophy?
With long-standing hypertrophy of either type, myocardial dysfunction may occur resulting in HF.

4. What is the relationship between the pressure gradient across a stenotic valve, the blood flow across the valve, and the valve area?
The pressure gradient across a valve is proportional to the blood flow across the valve divided by the valve area. The pressure gradient is a result of the flow across the stenotic valve and the degree of stenosis. For example, if flow remains the same and the valve becomes more stenotic over time, the
pressure gradient increases. How ever, an increased pressure gradient may not always mean that stenosis has progressed. For example, blood flow may increase with fever or anemia, resulting in an increased pressure gradient without any change in valve area. On the other hand, a decrease in the
pressure gradient does not mean an improvement in valve stenosis. For example, if myocardial function deteriorates and blood flow (cardiac output) decreases, the pressure gradient decreases. This decrease, how ever, does not reflect a less stenotic valve, but indicates a deterioration in myocardial
function because the heart can no longer pump the same blood flow.