Valvular disorders

Question 1

Describe aortic stenosis

Answer 1

-Narrow opening of aortic valve (resistance to flow causing turbulence)
-No problem with valvular closure
- The increase in afterload is larger than the increase in preload, there is an overall decrease in stroke volume
-Could result in a decrease in aortic pressure due to the decrease in stroke volume which leads to a decrease in cardiac output

Aortic stenosis causes a chronic increase in left ventricular volume and pressure
-Left ventricular pressure and volume overload occurs, leads to onset of pulmonary hypertension resulting in right ventricular dysfunction and eventually leading to congested heart failure (cardiomegaly)

Question 2

Describe mitral stenosis

Answer 2

-A diastolic murmur is presented between S2 and S1 due to higher velocities of blood flow (with elevated left atrial pressure) through the stenotic mutral valve into the left ventricle

Question 3

Describe aortic insufficiency

Answer 3

-Incomplete closure of aortic valve gives rise to regurgitation of blood back into left ventricle during diastole (aortic pressure is higher than that of the left ventricle during ventricular diastole), no problem opening valve

Question 4

Describe mitral insufficiency

Answer 4

-There are no true isovolumic relaxation and contraction phases in mitral regurgitated heart
-LV after preload in mitral regurgitated heart could be reduced because the total outflow resistance is reduced (atrial pressure is much lessure than the arterial and ventricular developed pressure)
-However there is a net decrease in the amount of blood ejected to the aorta due to the regurgitation back to the left atrium