Mitral Stenosis

Question 1

mitral valve stenosis: what?

Answer 1

smaller opening area of mitral valve

Question 2

mitral valve stenosis: almost always due to?

Answer 2

prior rheumatic fever

Question 3

what is rheumatic fever and the cause? most important damage?

Answer 3

auto immune reaction to group A strep infection of pharynx. antibodies develop 2-3 weeks after infection = affects heart, skin, joints and brain –> scar the heart valves = stenosis or regurgitation

Question 4

in acute rheumatic fever which valves are commonly affected

Answer 4

most commonly = mitral valve. then aortic valve. tricupsid and pulmonary valve rarely affected

Question 5

acute rheumatic fever and recurrence?

Answer 5

increase valve damage with each recurrence, so it’s best to prevent with chronic penicillin

Question 6

jone’s criteria for rheumatic fever requires?

Answer 6

evidence of group A strep infection and 2 major diagnostic criteria, or 1 major and 2 minor

Question 7

evidence of GAS infection? (3)

Answer 7

throat swab culture that grows strep A bacteria. antibodies to strep. toxin. recent scarlet fever (strep throat infection, strawberry tongue, rash).

Question 8

Jone’s Major criteria to diagnose acute rheumatic fever (5)

Answer 8

carditis (all layers of heart). migrating joint inflammation aka polyarthritis. rash (moving, red, central clearing aka erythema marginatum). subcutaneous skin nodules. chorea.

Question 9

Jone’s Minor criteria to diagnose acute rheumatic fever (4)

Answer 9

fever. blood tests that show inflammation (increased WBC, ESR). arthralgias (joint pain but no inflammation). increased PR interval on ECG (meaning longer AV delay)

Question 10

if the mitral valve is too tight, what happens to the the cardiovascular system?

Answer 10

need to get same amount of flow so high left atrial pressure –> stretches, then backpressure causes pulmonary artery and then right heart to have high pressures too

Question 11

hemodynamic curves in mitral stenosis

Answer 11

LV and aortic pressures stay the same, but left atrial pressure increases. larger transmitral gradient - in diastole instead of atrial coming down to same level of ventricular it stays high.

Question 12

mitral stenosis symptoms (4)

Answer 12

dyspnea. hemoptysis. fatigue. arrhythmias. atrial fibrillation

Question 13

why is there dyspnea in MS?

Answer 13

increased LA pressure = increased pulmonary venous/capillary pressures = fluid driven into lungs (lungs are stiffer, harder to breathe)

Question 14

dyspnea in MS gets worse if

Answer 14

you increase heart rate (shorter diastole, less time for atria to empty). increased flow (exercise, anemia, fever)

Question 15

orthopnea vs. paroxysmal nocturnal dyspnea?

Answer 15

orthopnea = SOB when lying flat (immediate increase in venous return when you lie down from blood pooled in lower extremities). PND = sudden dyspnea after lying flat for hours (slow reabsoprtion of tissue fluids that increases venous return)

Question 16

reason for hemoptysis in MS (coughing up blood)

Answer 16

increased in LA pressure = increased pulmonary venous pressure = get fragile bronchial vein collateral connections with pulmonary veins, which can rupture = bleed into lungs

Question 17

reason for fatigue in MS

Answer 17

increased LA pressure so increased pulmonary venous and artery pressure = scarring, so even more pressure = eventually right ventricular pressure is increased = RV dilates and fails, so insufficient forward output = fatigue, edema, ascites but less pulmonary congestion

Question 18

reason for arrhythmias in MS

Answer 18

increased in LA pressure = LA enlarges = increase likelihood of LA short circuits, which can cause chaotic atrial rhythm = fibrilation

Question 19

what is atrial fibrillation? what is the danger?

Answer 19

no organized atrial contraction, the atria jiggle = sluggish flow = blood clots = emboli.

Question 20

atrial fibrillation: what do you lose?

Answer 20

lose atrial kick = insufficient forward output = sudden increase in fatigue and SOB