CVS: Valvular Heart Disease

Question 1

Outline the pathophysiology of mitral stenosis

Answer 1

Rheumatic heart disease = autoimmune attack on the mitral valve produces thickening of the valve leaflets

Valve progressively narrows = resting diastolic mitral valve gradient, and hence left atrial pressure, increases = transudation of fluid into the lung interstitium = dyspnoea at rest or with minimal exertion

Haemoptysis = bronchial veins rupture

LA dilatation increases the risk for atrial fibrillation and subsequent thromboembolism

Question 2

What is the aetiology of mitral stenosis?

Answer 2

Rheumatic

Congenital

Malignant carcinoid

Prosthetic valve

Question 3

What are the symptoms and signs of mitral stenosis?

Answer 3

When <2cm

Dyspnoea

Fatigue

Palpitations

Haemoptysis

Malar flush

Low volume pulse

Auscultation: loud S1, opening snap, rumbling mid-diastolic murmur (best heard on expiration)

Question 4

What investigations should be performed when mitral stenosis is suspected?

Answer 4

ECG = AF, RVH

CXR = left atrial enlargement, pulmonary oedema, mitral valve calcification

ECHO

Doppler ECHO

Question 5

How should mitral stenosis be managed?

Answer 5

AF rate control and anticoag

Diuretics = decrease preload and pulmonary congestion

Balloon valvuloplasty

Valve replacement

Question 6

What are the possible complications of mitral stenosis?

Answer 6

Pulmonary HTN

Emboli

Pressure form large LA on local structures (recurrent laryngeal N, oesophagus)

Question 7

Discuss the pathophysiology of mitral regurgitation

Answer 7

Abnormal reversal of blood flow from the LV to the left atrium LA

MR results in volume overload of the LA and LV = chronic LV volume overload in MR results in increasing annular dilatation that leads to cascading effect and further increases in MR

Question 8

What are the causes of mitral regurgitation?

Answer 8

LV dilation

Annular calcification

Rheumatic fever

Infective endocarditis

Mitral valve prolapse

Ruptured chordae tendinae

Papillary muscle dysfunction

Cardiomyopathy

Congenital

Question 9

Outline the symptoms and signs of mitral regurgitation

Answer 9

Dyspnoea

Fatigue

Palpitations

AF

Displaced apex

RV heave

Pansystolic murmur at apex radiating to axilla

Question 10

What investigations should be performed when mitral regurgitation is suspected?

Answer 10

ECG = AF

CXR = enlarged LA + LV, mitral valve calcification, pulmonary oedema

ECHO

Doppler ECHO

Question 11

How should mitral regurgitation be managed?

Answer 11

AF rate control and anticoag

Diuretics

Surgery to repair or replace the valve

Question 12

What are the possible complications from mitral regurgitation?

Answer 12

HF

Pulmonary HTN

Question 13

Outline the pathophysiology of aortic stenosis

Answer 13

Senile degeneration of the valve

Outflow obstruction = increase in LV systolic pressure = compensatory mechanism to normalize LV wall stress, LV wall thickness increases by parallel replication of sarcomeres, producing concentric hypertrophy

Eventually, LV end-diastolic pressure rises = increase in pulmonary capillary arterial pressures and a decrease in CO due to diastolic dysfunction

Contractility of the myocardium may also diminish = decrease in CO due to systolic dysfunction, ultimately HF develops.

Question 14

What are the causes of aortic stenosis?

Answer 14

Senile calcification

Congenital = bicuspid valve

Rheumatic heart disease

Question 15

What is the classic triad of symptoms of aortic stenosis

Answer 15

1. Chest pain: Angina pectoris in patients with aortic stenosis is typically precipitated by exertion and relieved by rest
2. Heart failure: Symptoms include paroxysmal nocturnal dyspnoea, orthopnoea, dyspnoea on exertion, and SOB
3. Syncope: Often occurs upon exertion when systemic vasodilatation in the presence of a fixed forward stroke volume causes the arterial systolic blood pressure to decline

Question 16

What investigations should be performed when aortic stenosis is suspected?

Answer 16

ECG = LVH with strain pattern, poor R wave progression, LBBB or complete AV block

CXR = LVH, calcified aortic valve, post stenotic dilation of ascending aorta

ECHO

Doppler ECHO

Question 17

How is aortic stenosis managed?

Answer 17

Valve replacement

Percutaneous valvuloplasty/replacement

Question 18

What are the possible complications of aortic stenosis?

Answer 18

HF

Sudden death

Question 19

Describe the pathophysiology of aortic regurgitation

Answer 19

Diastolic reflux through the aortic valve can lead to LV volume overload = increase in systolic stroke volume and low diastolic aortic pressure produces an increased pulse pressure

Acute = LV does not have enough time to dilate in response to the sudden increase in volume = increase in pulmonary venous pressure

Chronic = LV enlargement and eccentric hypertrophy

Question 20

What are the causes of aortic regurgitation

Answer 20

Infective endocarditis

Ascending aortic dissection

Chest trauma

Congenital

CT disorder

Rheumatic fever

RA

SLE

HTN

Question 21

What are the symptoms and signs of aortic regurgitation?

Answer 21

Exertional dyspnoea

Orthopnoea

Paroxysmal nocturnal dyspnoea

Palpitations

Angina

Syncope

Collapsing pulse

Wide pulse pressure

High pitched early diastolic murmur

Carotid pulsation

Head nodding with each beat

Question 22

What investigations should be performed when aortic regurgitation is suspected?

Answer 22

ECG = LVH

CXR = cardiomegaly, dilated ascending aorta, pulmonary oedema

ECHO

Cardiac catheterisation

Question 23

How is aortic regurgitation managed?

Answer 23

ACEi = reduce systolic HTN

ECHO every 6-12m to monitor

Valve replacement

Question 24

What are the possible complications of aortic regurgitation?

Answer 24

HF

Sudden death

Arrhythmias