Surgery in Valvular and IHD

Question 1

What are some causes of cardiac ischaemia?

Answer 1

Atherosclerosis
Embolism
Coronary thrombosis
Aortic dissection
Arteritides
Congenital conditions

Question 2

What are the clinical manifestations of IHD?

Answer 2

Angina
MI
Arrhythmias
Chronic Heart Failure
Sudden Cardiac Death

Question 3

What are the two most dangerous manifestations of coronary artery disease

Answer 3

Left main stem stenosis

3 (Triple) vessel coronary artery disease

Question 4

When might you use coronary artery bypass grafting in a patient?

Answer 4

In symptomatic patients

If they have poor prognosis (left main stem stenosis, triple vessel disease)

Question 5

What is considered in determining a patient’s suitability for CABG surgery?

Answer 5

Adequate lung function
Adequate mental function
Adequate hepatic function
Ascending aorta be healthy
Distal coronary targets must be ok
LV EF >20%

Question 6

What vessels may be used in CABG?

Answer 6

Reversed saphenous vein
Internal mammary arteries
Radial arteries

Question 7

What are some problems associated with sternotomy?

Answer 7

Wire infection
Painful wires
Sternal dehiscence
Sternal malunion

Question 8

What are some typical post-op problems in CABG?

Answer 8

Cardiac tamponade
Death
Stroke

Question 9

What is cardiac tamponade?

Answer 9

Pericardial fluid exerting pressure on the heart

Primary features:

• raised CVP, HR
• low BP

Secondary features:

• oliguria
• increased O2 requirements
• metabolic acidosis

Treatment
- chest reopening

Question 10

What are the long-term outcomes post CABG?

Answer 10

50% have no further cardiac problems 10Y layer
Of the 50% who do, majority are minor issues, easily controlled with medication
5% may require repeat CABG

Question 11

What are the valves mostly operated on? Does it vary in children?

Answer 11

Aortic and mitral in adults

All four with roughly equal frequency in children

Question 12

What are some causes of valvular heart disease in adults?

Answer 12

Degenerative
Congenital
Infective
Inflammatory
LV or RV dilatation
Trauma
Neoplastic
Paraneoplastic

Question 13

What are the most common valve problems requiring surgery in Aberdeen?

Answer 13

Senile aortic valve stenosis (calcium deposition)
Bicuspid AS (congenital bicuspid aortic valve)
Degenerative MR

Question 14

How is aortic stenosis differentiated from aortic sclerosis in terms of signs?

Answer 14

Loss of S2 in stenosis, no loss in sclerosis

Question 15

When might surgery be recommended in mitral stenosis?

Answer 15

If MVA on echo is <1.5cm2

Question 16

What is a cardiopulmonary bypass?

Answer 16

Developed clinically in 1950s
Blood drained from RA and returned to ascending aorta
Heart and lung function taken over by CPB machine
Systemic anticoagulation required
Induced hypothermia
Non-pulsatile flow during CPB
Max time 12 hours
Max cardiac ischaemic time 6 hours

Question 17

What factors decide the choice of heart valve prosthesis?

Answer 17

Biological valve
- no warfarin required but valve wears out after 15 years

Mechanical valve
- lifelong warfarin, but valve lasts >40 years

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

Question 18

What organisms are associated with Rheumatic Fever, and which with endocarditis?

Answer 18

Streptococcal infections are related to rheumatic fever

Strep viridans is the most common endocarditis (subacute)
Staph aureus second most common (acute)

Infected valve may have been diseased beforehand or may have been normal

Question 19

In endocarditis, how does outcome vary in native vs prosthetic valves?

Answer 19

90% chance of cure with antibiotics alone in native valve

Only 50% in prosthetic

Chance of cure much higher with strep viridans than SA

Question 20

What are the indications for surgery in endocarditis?

Answer 20

Severe valvular regurgitation
Large vegetations
Persistent pyrexia
Progressive renal failure

Antibiotics are given IV for 6 weeks post-op