Lecture 11: Valve Dysfunction

Question 1

What is the sequence of events of the ventricular pressure-volume loop?

Answer 1

Aortic opening
Rapid ejection
Aortic closure
Isometric relaxation
Mitral opening
Diastolic filling
Mitral closure
Isometric contraction

Question 2

What is stenosis?

Answer 2

Restricted opening of a valve
Reduced flow
Higher pressure gradient
Upstream chamber
Eg. fibrosis = increased resistance and decreased compliance

Question 3

What is incompetence?

Answer 3

Imperfect closure
Reduced forward flow
Regurgitation
Upstream chamber - increased volume

Question 4

What is turbulence?

Answer 4

Irregular surfaces
High blood velocity
Results in murmurs
Turbulence with normal valves occur in high flow eg. children, fever patients, anemic people, pregnant women

Question 5

How does exercise impact valve dysfunction?

Answer 5

Increased demands of exercise exacerbate the hemodynamic difficulties of valve dysfunction

Question 6

What is aortic regurgitation?

Answer 6

Blood falls back into LV during diastole
LV volume overload
Eccentric cardiac hypertrophy
Therefore bigger SV is required, increase pulse pressure

Question 7

What is mitral regurgitation?

Answer 7

LV contraction results in blood entering the aorta and the left atrium during systole
Results in LV volume overload

Question 8

What is mitral stenosis?

Answer 8

Increased resistance across the mitral valve necessitates increased LA pressures to achieve flow and results in a pressure gradient across the mitral valve