Heart Valve Disease

Question 1

Aetiology of Aortic stenosis

Answer 1

• Vast majority due to ‘Degenerative’ calcific stenosis with tricuspid valve intervention in eight decade (elderly: 65+ 45% population)
• Bicuspid valves are a cause of earlier degeneration (5-6th decade)
• Less common causes include rheumatic disease (accompanied by mitral valve disease, 30-60), radiotherapy (fibrosis), congenital stenosis

Question 2

Pathophysiology of AS

Answer 2

-Progressive restriction of leaflets leads to Valvular obstruction resulting in:
=Hypertrophy and then fibrosis of the left ventricle due to pressure overload
=Inability to augment cardiac output

• Initial insult to endothelium of A valve
• Lipid and inflammatory cell infiltration (analogous to atherosclerosis)
• Fibrosis and calcification (progressive once established)

-Aortic stenosis causes ventricular pressure overload eventually leading to left ventricular dysfunction if untreated

Question 3

Symptoms of AS

Answer 3

• In general symptoms don’t appear until stenosis is severe
• Angina, often in the absence of obstructive coronary disease (ventricle hypertrophy= oxygen demand supply)
• Exertional syncope (diverted blood to muscles and vasodilatation requires increase in CO, cardiac decompensation)
• Dyspnoea (left atrium and pulmonary veins increase= heart failure)

=CHEST PAIN, SYNCOPE, BREATHLESSNESS

Question 4

Clinical signs AS

Answer 4

• Ejection systolic murmur (crescendo decrescendo)
• Quiet/ absent second heart sound (ejection of blood more prolonged when worsening, movement reduced so not closing with as much energy)
• Radiation to carotids
• Slow-rising pulse (restricted outflow= prolonged ejection and low volume)
• Forceful but not displaced (volume overloaded) apex beat (hypertrophy so pressure overloaded)

Question 5

Treatment of AS

Answer 5

-AS needs treatment when it is severe and:
=Patient has symptoms
OR
=LV function is deteriorating
-Medical treatment is not effective (mechanical problem): diuretics for HF
-Surgical aortic valve replacement (bioprosthetic can deteriorate/ mechanical)
-TAVI (trans-catheter valve implants) for those not eligible/ high risk- balloon expandable, durability?
-Assessment of symptoms and left ventricular function is critical to follow-up of patients with AS

Question 6

Prognosis of AS

Answer 6

• Prognosis of aortic stenosis even when severe is good when asymptomatic
• Once symptoms appear prognosis dramatically worsens

Question 7

Long-term care of AS

Answer 7

• Valve replacement improves symptoms in the vast majority of patients and returns them to a near-normal life expectancy although has some risks
• The goal of management is to intervene before irreversible myocardial damage without exposing asymptomatic patients to risks of AVR too early
• Timely surgical or trans-catheter treatment of AS can return prognosis to near-normal

Question 8

Risks of valve replacement AS

Answer 8

• Operative: death (~1-3%) , Stroke, PPM (pacemaker)
• Long-term: Endocarditis (~0.5%/ year), Thrombo-embolism, Bleeding with anticoagulation (mechanical AVR), valve degeneration bioprosthetic)

Question 9

Investigations of AS

Answer 9

• ECG= large complexes, strain pattern (T wave inversion in 5 and 6)= left ventricular hypertrophy
• Echo= leaflets thickened and calcified, hypertrophied LV
• Doppler= speed of blow flow across valve= faster velocity
• Transthoracic Echo= trace valve
• CT= heavy calcification, volume of calcium

Question 10

Aetiology and pathophysiology of Primary MR

Answer 10

-Primary= related the valve itself between left atrium and ventricle, anterior and posterior leaflets)
=Degenerative (most common, includes myxomatous disease and mitral valve prolapse)
=Rheumatic heart disease (with MS)
=Infective endocarditis (leaflet perforation or caudal rupture)
=Acute myocardial infarction (papillary muscle rupture, rare, urgent surgery)

Question 11

Aetiology and pathophysiology of Secondary MR

Answer 11

-Secondary= caused by dysfunction of the surrounding structure
=Left ventricular dysfunction/ cardiomyopathy (distortion of the sub-valvular apparatus)

Question 12

Symptoms of MR

Answer 12

• Usually asymptomatic (left atrium compliance increases, LV dilatation for volume overload)
• Dyspnoea – mainly on exertion (heart failure)
• Orthopnoea / paroxysmal nocturnal dyspnoea
• Fatigue
• Palpitations (if the patient goes into AF)
• Swelling of ankles/ pitting oedema

Question 13

Clinical signs of MR

Answer 13

• May find an irregular pulse (AF)
• Blood pressure and pulse pressure are usually normal
• Hyperdynamic displaced apex beat laterally
• Pansystolic murmur – heard loudest at the apex, usually radiating to the axilla (depending on anterior or posterior leaflet affected)
• Signs of congestive heart failure may be present (elevated JVP, lung crepitations, pitting edema in lower limbs)

Question 14

Investigations of MR

Answer 14

-Echocardiogram (single most useful test)
=Useful to diagnose MR, assess cause and severity of MR
=Also useful to assess LV size/function and assess for pulmonary hypertension
=Transthoracic echo is suitable for most cases
=Transoesophageal echo may be needed for patients with severe MR being considered for intervention

-ECG
=May see atrial fibrillation or a broad notched p wave

-Chest X-ray
=May see cardiomegaly and/or signs of congestive heart failure

Question 15

Treatment of severe chronic primary MR

Answer 15

-Ongoing medical therapy with close follow-up (HF and AF)
-Mitral valve repair/replacement
-Transcatheter mitral valve intervention (Mitraclip)
=May be considered in patients with high surgical risk

Question 16

Follow up of MR patients

Answer 16

-Asymptomatic patients with moderate MR and normal LV function
=Outpatient review every year with transthoracic echo every 1-2 years

-Asymptomatic patients with severe MR and normal LV function
=Outpatient review and transthoracic echo every 6 months

Question 17

Indications for mitral valve surgery in severe MR

Answer 17

-Symptoms + LV Ejection Fraction > 30%
-Asymptomatic + any of the following:
=LV Ejection Fraction < 60%
=Dilated LV (i.e. LV end-systolic diameter > 45 mm)
=New onset AF
=Pulmonary hypertension (pulmonary artery systolic pressure > 50 mmHg)

-Mitral valve repair where possible preferred over replacement

Question 18

Treatment of secondary/functional MR

Answer 18

-Medical treatment of underlying cardiomyopathy
=E.g. Diuretics, ACE-inhibitors, beta-blockers, spironolactone

• Cardiac resynchronization therapy device may help
• Some emerging evidence for transcatheter mitral valve intervention

Question 19

What is AR?

Answer 19

-Aortic valve- 3 cusps, LV outflow tract and ascending aorta
-AR occurs due to either dysfunction of AV cusps or dilatation of the aortic root/ascending aorta or both mechanisms
=allows reflux back into LV chamber in diastole (inadequate closure)
-More common in men than women (Marfan syndrome)
-Stenosis and regurgitation can happen at same time

Question 20

Aetiology of Primary valve disease (AR)

Answer 20

-Cusps not working properly

• Rheumatic fever (most common in developing) (1)
• Endocarditis (2)
• Bicuspid aortic valve (congenital= most common developed)
• Myxomatous prolapse
• Trauma
• Collagen vascular disease (3)
• Degenerative valve disease (senile)!
• Prosthetic valve regurgitation

Question 21

Aetiology of aortic root abnormalities

Answer 21

-Dilatation (stretching annulus where attached so cannot close), disease of aortic root/ ascending aorta

• Systemic hypertension
• Marfan syndrome/ EDS!
• Aortitis
• Trauma/ dissecting aneurysm
• Idiopathic or senile aortic dilatation
• Spondylarthropathies

Question 22

Pathophysiology of AR

Answer 22

-Backward flow of blood from aorta into LV (diastolic)

=Rapid fall of aortic pressure during diastole
==Increased pulse pressure

=Increased LV volume and pressure
==Increased LA pressure - Increased pulmonary venous pressure - Pulmonary oedema
==Increased SV (Frank-Starling Mechanism) - Peak systolic pressure increased as increased SV ejected into aorta - increased pulse pressure
==Increased diastolic wall-tension produces eccentric hypertrophy

Question 23

Symptoms AR

Answer 23

-Patients may be asymptomatic, especially in chronic AR
-Dyspnoea
=Initially on exertion
=Paroxysmal nocturnal dyspnoea (LV decompensates)
=Orthopnoea
-Palpitations
-Peripheral oedema (HF)
-Light-headedness, syncope (v low diastolic pressure)
-Angina

Question 24

Clinical signs AR

Answer 24

-Pulse
=Tachycardia
=Large volume, collapsing (Water-hammer),
=Wide pulse pressure (large difference in systolic and diastolic pressure 50mmHg)!, Corrigan sign (carotid artery)

-Displaced Apex (dilated LV)

-Early diastolic murmur
=Best heard along left sternal border @ 3rd/4th ICS with patient sitting leaning forward on peak expiration

• Features of hyperdynamic circulation (large difference in pressure)- e.g deMusset’s (constant head bobbing movement), Quincke’s pulses (blushing and blanching nail bed), Duroziez’s sign (diastolic bruit at femoral artery), Traube’s (pistol shot), etc
• Clinical features of HF- JVP, Bibasal crackles, hepatomegaly, peripheral oedema

Question 25

Investigations AR

Answer 25

-Blood tests
=To investigate for endocarditis
-CXR
=Cardiomegaly
-ECG
=Sinus tachycardia
=LVH
-Echocardiography!
=Confirms diagnosis, identifies cause of regurgitation and assesses for severity

Question 26

Treatment of AR

Answer 26

• Management of AR depends on the presentation
• Patients with Mild-Moderate AR are followed up regularly with serial echocardiography

-Surgical treatment- for severe AR
=Aortic Valve replacement- Tissue vs mechanical valve
=+/- Aortic root/ascending aorta surgery

-Medical management
=For heart failure
==Diuretics, salt restriction
==Vasodilators
=Control of arrhythmia- betablockers/Digoxin, anticoagulation
=Treatment of Endocarditis- Antibiotics

Question 27

Prognosis and long-term care AR

Answer 27

• Patients diagnosed with AR should be regularly followed up in cardiology clinic and surgical valve intervention planned if patients become symptomatic or develop LV dysfunction as assessed by echocardiography
• Patients with acute severe AR are usually haemodynamically unstable and require urgent surgery compared to patients with chronic AR which is well tolerated over decades
• All patients who undergo AV surgery are followed up in cardiology clinics
• All patients who have mechanical aortic valve replacement remain on lifelong Warfarin

Question 28

Describe the Water hammer pulse

Answer 28

• Collapsing
• Rapid, abrupt and forceful upstroke and descent
• Hyperdynamic circulation
• Low filling resistance in blood vessels into which the LV pumps blood

Question 29

Causes of Mitral stenosis

Answer 29

-Rheumatic fever!!!
-Degenerative disease
-Congenital

Question 30

Presentation of Mitral stenosis

Answer 30

-Progressive symptoms of breathlessness (increased atrial pressure= pulmonary venous hypertension)
-Haemoptysis (pink frothy)
-Malar flush
-AF
-Fatigue
-Sequelae of thromboembolism (AF)

Question 31

Investigation of MS

Answer 31

-CXR: left atrial enlargement
-ECHO: stenosis

Question 32

Management of MS

Answer 32

-Percutaneous mitral valve commissurotomy/ balloon valvotomy
-Mitral valve repair or replacement
-Medical therapy for heart failure and AF (warfarin)

Question 33

Causes of tricuspid regurgitation

Answer 33

-Right ventricular infarction
-Pulmonary hypertension e.g. COPD
-Rheumatic heart disease
-Infective endocarditis (especially intravenous drug users)
-Ebstein’s anomaly
-Carcinoid syndrome

Question 34

Signs of tricuspid regurgitation

Answer 34

-Pan-systolic murmur
-Prominent/giant V waves in JVP
-Pulsatile hepatomegaly
-Left parasternal heave