Met 2: Cardio; Lec. 5 Mitral Valve Disease

Front 1

Describe the anatomical components of the mitral valve.

What two regions does the mitral valve separate?

Back 1

- Annulus

- Two leaflets (Anterior and Posterior)

- Chordae (attach the leaflets to the papillary muscles)

- Papillary Muscles

Separates the left atrium from the left ventricle.

Front 2

The mitral valve is separated from which valve my a curtain?

Which leaflet (anterior or posterior) is larger in the mitral valve?

Back 2

Aortic valve

The anterior leaflet.

Front 3

At which letter on the Wigger's diagram does the mitral valve open?

At which letter does it close?

Back 3

Opens - f

Closes - b

Front 4

What is the most common cause of mitral stenosis?

2 other causes? One the was specified the other I like

Back 4

Rheumatic fever.

tumors of the left atrium - myxoma and endocarditis with large vegetation

Front 5

What is rheumatic fever?

What are common symptoms and what is the treatment?

Back 5

Inflammatory condition leading to a complicated URTI due to Group A Strep.

Sx - chills, fever, fatigue, migratory arthralgias, other sx as per Jones Criteria

Tx - Anti-inflammatory and penicillin

Front 6

Describe the Jones criteria (major and minor) for rheumatic fever.

Back 6

Major
1) Carditis
2) Polyarthritis
3) Chorea
4) Erythema marginatum
5) Subcutaneous nodules

Minor
1) Arthralgia
2) Fever
3) Elevated ESR or CRP
4) EKG eveidence of prolonged PR interval

Diagnosis requires 2 major criteria, or 1 major and 2 minor with preceding evidence of strep infection.

Front 7

Describe the pathology (cause) of mitral stenosis.

Back 7

Inflammation produces fibrous thickening and calcification, the commisures fuse, there is chordal thickening and shortening, leading to poor valve compliance.

Front 8

Describe the pathophysiology (systemic consequences) of mitral stenosis.

Back 8

The poorly functioning valve leads to a pressure build-up in LA, which may lead to pulmonary hypertension and RHF.

Front 9

What is the normal size of the mitral valve (cm^2) and when is stenosis considered significant?

Back 9

Normal: 4-6 cm^2

Hemodynamically significant stenosis: < 2 cm^2

Front 10

What are some symptoms of severe mitral stenosis?

Back 10

SOBOE and reduced exercise capcity

Pulmonary congestion at rest, leading to orthopnea and PND

Pulmonary hypertension leading to RHF

Hoarseness due to LA enlargement, compressing the recurrent laryngeal nerve.

Front 11

What are some complications of MS?

Back 11

endocarditis
Afib
hemoptysis
thrombus formation

Front 12

What is found with auscultation in mitral stenosis?

Back 12

Loud S1 (in early disease, soft S1 in late disease), opening snap following S2 (stiff valve).

Murmur is low pitched, diastolic rumble with pre-systolic accentuation.

Front 13

What investigations would you order to evaluate mitral stenosis?

Back 13

ECG - LA enlargement, +/- RVH, atrial fibrillation

CXR - LA enlargement, pulmonary vascular redistribution, edema, Kerley B lines

Echocardiography – visual assessment of valve, velocity of blood across the valve allows us to estimate the pressure gradient and MVA (mitral valve area)

Front 14

What are the pharmacological and surgical interventions for treatment of mitral stenosis and what are the indications?

Back 14

Pharmacological:
Diuretics (for pulmonary hypertension)
Beta-blockers or CCB (decrease HR)
Anticoagulants (only if in atrial fibrillation)

Surgery:
Percutaneous valvuloplasty

Mitral Valve replacement (in patients where valvuloplasty is not suitable i.e. LA clot, severe calcification, MR)

Front 15

What is the most common cause of mitral regurgitation? What can cause this?

Back 15

Mitral valve prolapse.

Excess tissue makes the valve floppy, May be associated with Marfan's and Ehler's Danlos

Front 16

What are some other causes of MR? Remember your anatomy

Back 16

annulus - mitral annular calcifications
leaflets - MVP, rheumatic, endocarditis, systolic anterior motion
chordae - rupture
papillary - dysfunction, rupture
LV - cavity dilation

Front 17

What is the pathophysiology (systemic consequences) of mitral regurgitation?

Back 17

A portion of the LV stroke volume is ejected back into the LA during systole. As a result, forward CO is reduced. LA volume and pressure increase and volume related stress on LV - SV increases.

Over time, the dilated LA returns to normal pressure, the LV dilates and high SV maintained, leading to eventual LV failure.

Front 18

What are the typical presentations of acute and chronic mitral regurgitation?

Back 18

ACUTE - Pulmonary edema leading to dyspnea, orthopnea, PND.

CHRONIC - Sx of low cardiac output, fatigue, weakness, SOB with exertion

Once the patient starts to decompensate, they will begin to experience orthopnea, PND, Sx of right heart failure such as edema

Front 19

What is found with auscultation in mitral regurgitation?

Back 19

- Pansystolic murmur at the apex radiating to axilla (most often)

- S1 may be soft (depending on etiology)

- S3 present (chronic)

- Displaced apex (chronic)

- Signs of R heart failure if acute or decompensated chronic (elevated JVP, edema)

Front 20

What physiologic factor make MR better/ worse?

Back 20

better - decreased afterload (medical interventions)

worse - increased afterload (hypertension, aoritc stenosis)

Front 21

What would you order to investigate mitral regurgitation?

Back 21

"CXR - pulmonary edema if acute. If chronic, LA/LV enlargement

ECG - LA enlargement, LVH if chronic

ECHO - important to evaluate LV size and function, mechanism and degree of MR.

Cath - measure pressure, check coronaries, degree of MR

Front 22

What are the pharmacological treatments for mitral regurgitation?

Back 22

ACUTE - diuretics and vasodilators

CHRONIC - some evidence for use of ACE-I (to reduce afterload) if HTN or LV dysfunction

Surgery is usually recommended

Front 23

What are the criteria for surgery in chronic mitral regurgitation?

Back 23

- Severity of symptoms

- Reduction in EF

- LV dilatation

- New-onset atrial fib / PHTN

- Whether or not valve is repairable