Valvular heart disease Surgery - therapy

Question 1

* What are the causes of cardiac ischaemia?

Answer 1

• Atherosclerosis
• Embolism – blood clot forms on aortic valve
• Coronary thrombosis
• Aortic dissection – tear on inside of the aorta – blood dissects into the inside of the aorta – creates an extra space between aortic layers – this wall expands at the expanse of the true lumen
• Arteritides – inflammation of the arteries
• Congenital

Question 2

* What are the manifestations of ischaemic heart disease?

Answer 2

• Angina
• MI
• Arrythmias
• Chronic heart failure
• Sudden death

Question 3

* What are the Dangerous patterns of Coronary Artery Disease?

Answer 3

• Left main stem stenosis
• 3 vessel coronary artery disease – where the narrowing is near the origin of the coronary artery there is a risk of sudden death

Question 4

*Which patients are suitable for CABG?

Answer 4

• Adequate lung function
• Adequate mental function
• Adequate hepatic function
• Ascending aorta OK
• Distal coronary targets OK
• LV EF > 20%

Question 5

What is the surgical treatment for treatment of ischaemic heart disease?

Answer 5

CABG,

. Coronary artery disease (CAD) is the narrowing of the coronary arteries – the blood vessels that supply oxygen and nutrients to the heart muscle

Question 6

What are the possible conduits for CABG?

Answer 6

• Reversed saphenous vein
• Internal mammary arteries _ left one – branch of the subclavian artery – normally supplies blood to the breasts
• Radial arteries – radial is the easier artery to get out of the arm than the ulnar

Question 7

What are long term outcomes for CABG?

Answer 7

• 50% have no further cardiac problems 10 years later
• Of the 50% who do have a problem, the majority are minor and easily controlled with medication
• 5% of patients may require repeat CABG
• Risk of death for a second CABG is much higher – 10%

Question 8

Where does the cardioplumonary bypass machine pass blood to and from?

Answer 8

• Blood drained from the RA and returned to the ascending aorta

Question 9

What is the function of the CPB machine?

Answer 9

• Heart and lung function taken over by CPB machine

Question 10

What is the main problem of CPB machines?

Answer 10

Coagulopathy

Question 11

When is air embolism more common?

Answer 11

• Air embolism is more common in open cardiac surgical procedures such as valve replacement than in closed cardiac operations such as CABG

Question 12

What are the sternotomy related problems associated with surgery?

Answer 12

• Wire infection
• Painful wires
• Sternal dehiscence – wires are cut through the sternum – can be as a result of osteoporosis
• Sternal malunion

Question 13

What are the Post-op problems in cardiac surgery?

Answer 13

Cardiac Tamponade

Death

Stroke

Question 14

What is cardiac tamponade?

Answer 14

Compression of the heart by an accumulation of fluid in the pericardial sac - prevention of filling properly in the atria

Question 15

What are the features of cardiac tamponade?

Answer 15

Primary features – Raised CVP, raised heart rate, low BP

Secondary features – Oliguria, increased oxygen requirements, metabolic acidosis

Question 16

What is the treatment for cardiac tamponade?

Answer 16

Chest - reopening

Question 17

What are the common valve surgeries in adults?

Answer 17

Mainly aortic and mitral valve surgery

Question 18

What are the common valve surgeries in children?

Answer 18

• All four heart valves operated with roughly equal frequency

Question 19

What are the commonest valve problems requiring cardiac surgery in aberdeen?

Answer 19

• Senile Tricuspid aortic stenosis
• Bicuspid aortic stenosis
• Degenerative MR

Question 20

What is the presentation of aortic stenosis?

Answer 20

Presents as heart failure, angina, syncopal episodes or as an asymptomatic incidental finding

• The murmur is usually easily heard

Question 21

ECG/ECHO findings for aortic stenosis?

Answer 21

Left ventricular hypertrophy

Question 22

What is the likely AV gradient for aortic stenosis?

Answer 22

Above 50mmHg

Question 23

When is atrial valve replacement recommended?

Answer 23

Severe aortic stenosis

Question 24

What is the typical presentation for aortic regurgitation?

Answer 24

Heart failure, angina, or as an asymptomatic incidental finding

• The murmur is usually difficult to hear
• The louder the murmur the more severe the AR

Question 25

When is aortic valve replacement necessary for aortic regurgitation?

Answer 25

• Recommended for severe AR especially with LV dilatation
• In severe AR the entire LV is filled with contrast after one diastolic interval during aortography

Question 26

Describe the murmur of mitral stenosis?

Answer 26

• Murmur is usually difficult to hear
• If easily heard then the stenosis is severe
• May have to exercise the patient to hear the murmur
  
  • Presystolic accentuation may be present

Question 27

When is surgery recommended for mitral stenosis?

Answer 27

If MVA (mitral valve area) on ECHO is < 1.5cm2

Question 28

Describe the murmur of mitral regurgitation

Answer 28

• Murmur is usually easy to hear
• If murmur is loud, MR is usually severe

Question 29

What is severe mitral regurgitation associated with?

Answer 29

LV and LA dilatation, onset of AF and pulmonary hypertenison

Question 30

When is mitral valve replacement necessary for mitral regurgitation?

Answer 30

When there is severe MR present

• Severe MR on ECHO characterised by systolic blood flow reversal in the pulmonary veins

Question 31

What are the common causes of valvular heart disease in the adult?

Answer 31

• Degenerative – aotric or mitral valve – calcium forming in the valve – 10% of people over the age of 70. Degenerative mitral valve disease refers to mitral regurgitation
• Congenital – bicuspid aortic stenosis – middle age – aortic stenosis
• Infective – Endocarditis (sub – acute bacterial endocarditis streptococcus vividens from dental practice)(acute endocarditis – staph aureus – usually from drug abusers
• Inflammatory

Question 32

What is the typical pathology of rheumatic fever?

Answer 32

Pancarditis

Related to streptococcal infections

Skin and joint manifestations are usual – migratory erythema – blotchy red skin, sore joints

treated with aspirin and bed rest.

Question 33

What are the different types of vavles?

Answer 33

Biological valve and mechanical valve

Question 34

Describe the biological valve

Answer 34

• No warfarin required but the valve wears out after 15 years

Question 35

Describe the mechanical valve

Answer 35

• Last 40/50 years– Warfarin required for life. Valve lasts for > 40 years - Counselling for warfarin – can do high risk activity – head injuries are now likely to be fatal

Question 36

What is a common treatment of mitral regurgitation?

Answer 36

Mitral valve repair,

• possible in many cases of degenerative MR. When complete valve competence is restored, repair is better than replacement for the mitral valve.

Question 37

What gives rise to sub-acute and acute endocarditis?

Answer 37

• Strep viridans the commonest organism – gives rise to subacute bacterial endocarditis
• Staph aureus the second commonest organism – gives rise to acute bacterial endocarditis

Question 38

What is the likelihood of cure with antibiotics alone of NVE and PVE?

Answer 38

• NVE (native valve endocarditis)- 90% chance of cure with antibiotics alone
• PVE (prosthetic valve endocarditis)– 50% chance of cure with antibiotics alone
• Chances of cure much higher with strep viridans endocarditis than with staph aureus

Question 39

What are the indications for surgery in endocarditis?

Answer 39

• Severe valvular regurgitation – once the valve has been destroyed
• Large vegetations – vegetation can break off and cause stroke
• Persistent pyrexia – inability to control the infection
• Progressive renal failure – glomeruli inflammation – permanent renal damage

Antibiotics are given IV for 6 weeks post-operatively – kept in hospital for this