Mitral Stenosis 2

Question 1

atrial fibrillation: what does it do to heart rate?

Answer 1

atrial fires 300-600 bpm, AV node filters out 2/3 of them but you still increase heart rate 2 - 3 X

Question 2

atrial fibrillation: what happens with HR > 120

Answer 2

often only 1/3 cycle is spent in diastole (vs. normally 2/3 of cardiac cycle when at resting HR). so less time to empty LA past tight mitral valve = sudden increased SOB, fatigue (also sudden pulmonary edema)

Question 3

atrial fibrillation and clot risk why? where? what can happen?

Answer 3

stretch of atria = short circuits = loss of atrial pumping. LA appendage most prone. clots can mobilize to any organ = strokes, heart attacks.

Question 4

any process that ____ can lead to atrial fibrillation?

Answer 4

increases LA pressure (because it stretches the LA). so any long standing left heart valve disease, or any heart failure type will lead to A fib!

Question 5

north america: most common causes of A fib

Answer 5

age and hypertension (b/c stiff LV = higher LA pressure, so LA enlargement = A fib risk)

Question 6

A fib: always need to consider?

Answer 6

if the clot risk is high enough to put them on life long anticoagulation.

Question 7

A fib almost always leads to? so you will need?

Answer 7

increased heart rate - so you’ll need HR control drugs

Question 8

right atrial stretch can be caused by? leads to?

Answer 8

any process that increases right heart diastolic pressure (pulmonary hypertension, right valve disease) can stretch AR = atrial fibrillation

Question 9

MS physical exam: heart sound findings?

Answer 9

louder S1. opening snap. mitral rumble aka a murmur.

Question 10

why loud S1 in MS? opening snap?

Answer 10

thickened leaflets/chords generate a louder sound, might even be palpable. when more rigid, S1 intensity gradually decreases. opening snap from MV opening, will also disappear when valve very rigid/calcified.

Question 11

diastolic murmur in MS: describe it? cause? worse MS means?

Answer 11

low pitched rumble with pre-systolic accentuation (atrial kick increases its intensity). caused by MV turbulent flow. worse MS = longer into diastole the murmur lasts

Question 12

in very severe MS what happens to the heart sounds?

Answer 12

OS moves closer to S2. mitral rumble ecomes longer

Question 13

MS physical sign for RV?

Answer 13

RV overload = enlarged and hypertrophied RV = parasternal lift/RV heave (palpable lift underneath sternum).

Question 14

other signs of MS in physical?

Answer 14

right sided S3/4 because of abnormal RV diastolic function. dilated RV can also lead to tricuspid regurgitation

Question 15

what tests would you do for MS?

Answer 15

ECG. CXR. echocardiogram. cardiac catheterization

Question 16

ECG findings for MS

Answer 16

enlarged LA, RV hypertrophy, A fib. no LV problems

Question 17

CXR findings for MS

Answer 17

calcified MV, enlarged LA. pulmonary venous engorgement. pulmonary interstitial edema = kerley B lines. if sever, you can also see pulmonary alveolar edema, RV enlargement, enlarged pulmonary arteries

Question 18

natural progression of MS?

Answer 18

5-10 year latencies between: rheumatic fever to signs of MS, to mild symptoms, to A fib, to severe symptoms, to death

Question 19

prevention of MS?

Answer 19

prevent rheumatic fever by treating GAS early and decreasing overcrowding. prevent recurrences of RF w/ monthly intramuscular penicillin shots. don’t need endocarditis prophylaxis, just maintain good dental hygeine

Question 20

drug therapy for mitral stenosis

Answer 20

diuretics to decrease volume load on LA/lungs/RV. rate slowing drugs especially in A fib (will slow heart rate = longer diastole to empty LV) = beta blockers or Ca channel blockers. anticoagulants (coumadin aka warfarin) for A fib or if prior emobli

Question 21

balloon valvuloplasty: what? when is it useful?

Answer 21

deflated balloon at end of long catheter - push across atrial septum and inflated to crack open the fused MV. useful if MV isn’t severely calcified and if there is no major regurgitation

Question 22

surgical therapy for MS: name? what?

Answer 22

commissurotomy: open heart surgery with cardiopulmonary bypass machine, surgeon cuts open MV commissures. can also have survery-valve replacement with tissue or metal valve