SM 141 Valvular Heart Disease

Question 1

What is the main cause of Mitral Stenosis?

Answer 1

Rheumatic Fever -> Rheumatic Heart Disease

Question 2

Describe the global burden of Rheumatic Heart Disease?

Answer 2

Rare in developed countries with antibiotics to treat Strep infections, common in developing countries

Question 3

How does Mitral Stenosis affect the Left Atrium?

Answer 3

Mitral Stenosis increases the contraction pressure of the Left Atrium

Question 4

What is Mitral Stenosis?

Answer 4

Thickening of the Mitral Valve that leads to LV Hypertrophy, decreased LVEDV and decreased SV

Question 5

How does the increase in Left Atrial pressure affect the lungs?

Answer 5

Increased Left Atrial pressures leads to fluid backup into the lungs, causing fluid to accumulate in the alveoli

Question 6

How does Mitral Stenosis affect the right side of circulation?

Answer 6

Increased Left Atrial pressure -> pulmonary congestion -> increase pulmonary pressure -> increase RV/RA Pressure = systemic venous congestion

Question 7

Does Mitral Stenosis cause systemic congestion or pulmonary congestion?

Answer 7

Both; increasing pulmonary pressure causes congestion that ultimately induces systemic congestion because the 2 circuits of the heart are in series

Question 8

How does Mitral Stenosis affect cardiac output?

Answer 8

Decreased LVEDV = Decreased CO

Question 9

How does Mitral Stenosis affect the Left Atrium and what does it predispose?

Answer 9

Increased LA Pressure causes dilation of the LA, which leads to Fibrosis -> Atrial Fibrillation -> Embolism formation

Question 10

What heart sound indicates LV Hypertrophy?

Answer 10

S4 - always pathologic

Question 11

What heart sound indicates LV Dilation?

Answer 11

S3 - may be pathologic, can be normal in pregnancy

Question 12

What does an S4 sound indicate and when does it occur?

Answer 12

S4 indicates loss of compliance of the LV leading to LV Hypertrophy

Question 13

What does an S3 sound indicate and when does it occur?

Answer 13

S3 indicates the LV is overfilled with blood and leads to LV Dilation

Question 14

How does Mitral Stenosis affect the Venous return curve?

Answer 14

Increased pressures in the Left Atrium shift the entire curve upward, so that S1 occurs later and Ventricular filling occurs earlier

Question 15

What murmur presents with an opening snap?

Answer 15

Mitral Stenosis, seen as the presystolic potentiation on the upward shifted venous return curve

Question 16

What are the physical findings of Mitral Stenosis?

Answer 16

Loud S1, opening snap, diastolic rumble

Question 17

How does Mitral Stenosis progress with time?

Answer 17

Calcification and thickening of the Mitral Valve continues, leading to increased LA dilation and pressure

Question 18

What can be used to quantify the extent of Mitral Stenosis?

Answer 18

Ultrasound w/ Doppler, which measures fluid velocity; increased velocity = greater stenosis

Question 19

How does Atrial Fibrillation affect Mitral Stenosis?

Answer 19

Increased risk of embolism formation

Question 20

What is a “paroxysmal” rhythm?

Answer 20

One that is entered and exited randomly

Question 21

How does Mitral Stenosis progress?

Answer 21

Mitral Stenosis progresses over time, varying from mild increases in LA Pressure + RA Pressure + CO only during exercise to increases in LA Pressure + RA Pressure + Decreased CO at rest

Question 22

When should Mitral Stenosis be treated and why?

Answer 22

Immediately after detected, especially if the patient is symptomatic, because it worsens with time

Question 23

What is the treatment for Mitral Stenosis?

Answer 23

Mitral Commisurity, which cleaves the calcified commisures to restore valve function, as well as balloon inflation

Question 24

What causes a bicuspid Aorta?

Answer 24

Normally tricuspid, due to Congenital Aortic stenosis

Question 25

How can Aortic Stenosis arise?

Answer 25

Congenital AS, Rheumatic AS, and Calcification AS

Question 26

Why do valve problems occur on the Left side of the heart?

Answer 26

Left side is a high pressure system, Right side is not

Question 27

Why is a bileaflet Aortic Valve inherently stenotic?

Answer 27

Doesn't open as much as Trileaflet Aortic Valve

Question 28

How does Aortic Stenosis affect the Left Ventricle?

Answer 28

Increased LVEDP and decreased SV

Question 29

Why does Aortic Stenosis cause LV Hypertrophy?

Answer 29

LV needs to hypertrophy to reach higher pressures and overcome increased afterload from Aortic Valve

Question 30

How does Aortic Stenosis affect LV and Aortic pressures?

Answer 30

LV has to reach higher pressure to eject blood and therefore the Aortic pressure decreases

Question 31

Why does Aortic Stenosis produce a crescendo-decrescendo murmur?

Answer 31

High increase in pressure to overcome stenotic Aortic valve causes crescendo while drop in pressure causes decrescendo

Question 32

What are the physical exam findings for Aortic Stenosis?

Answer 32

Delayed Carotid impulse due to higher pressure needed for ejection, systolic thrill, paradoxical S2

Question 33

What is a thrill?

Answer 33

Feel the murmur from the heart

Question 34

Explain the mechanism behind paradoxical splitting of S2?

Answer 34

Normal S2 splitting results in Pulmonary Valve closing after Aortic Valve due to increased blood flow and decreased thoracic pressure through the Right Ventricle; Paradoxical splitting in Aortic Stenosis causes the Aortic Valve to close after the Pulmonary valve because it reaches a higher peak pressure to overcome increased afterload

Question 35

What valvular defect causes paradoxical splitting of S2?

Answer 35

Aortic Stenosis

Question 36

When is the optimal time to operate in Aortic Stenosis patients and why?

Answer 36

Only operate after symptoms develop, because they decline rapidly and there is no evidence to support early intervention

Question 37

What are symptoms of Aortic Stenosis?

Answer 37

Dyspnea, Angina, Syncope

Question 38

What is the treatment for Aortic Stenosis?

Answer 38

Operate and replace Aortic Valve with either a prosthetic valve or a mechanical valve?

Question 39

How do prosthetic vavles compare to mechanical valves?

Answer 39

Prosthetic valves are made of non-thrombogenic material so clots don't form and blood thinners aren't need, but they're less durable; Mechanical valves are made of metal and form clots, so blood thinners are needed, but they're more durable

Question 40

What is the newest treatment for Aortic Stenosis?

Answer 40

TAVR = Transaortic Valve Replacement