Week 5 - Valvular and Ischaemic Heart Disease Therapy

Question 1

What are the main causes of cardiac ischaemia?

Answer 1

atherosclerosis
embolism
coronary thrombosis
aortic dissection
congenital

Question 2

What are the manifestations of ischaemic heart disease?

Answer 2

angina, MI, arrhythmia, chronic heart failure, sudden death

Question 3

What are indications for CABG?

Answer 3

• if percutaneous intervention via stent isn’t possible,
• prognostic reasons,
• adequate lung, hepatic and mental function, ascending aorta ok

Question 4

What can be used as a conduit for CABG?

Answer 4

• inverted saphenous vein (valves)
• internal mammary arteries
• Radial arteries

Question 5

What is the process of CABG?

Answer 5

• sternotomy
• put patient on cardiopulmonary bypass - potassium rich to heart to stop it pumping

Question 6

What are sternotomy related problems?

Answer 6

• wire issues - infection, pain, snap and damage other tissues

Question 7

What are a major post-op CABG issues?

Answer 7

• cardiac temponade
• stroke
• death

Question 8

What are the long term outcomes post CABG?

Answer 8

• 5% require repeat CABG
• 50% have no further cardiac issues 10yrs later

Question 9

Which valves are mainly operated on?

Answer 9

• in adults, aortic and mitral (left)
• in paediatrics, all 4 with equal frequency

Question 10

What are the main causes of valvular issues?

Answer 10

• RHD/infective endocarditis
• degenerative
• congenital
• functional issue
• trauma

Question 11

What is rheumatic fever?

Answer 11

pancarditis (inflammation of all 3 layers of heart|). begins with strep throat and may end in rheumatic heart disease.

Question 12

What is bacterial endocarditis?

Answer 12

infection of inner layer of heart, affecting valves. strep viridans and staph aureus give rise to bacterial endocarditis.

Question 13

What is the likelihood of cure of endocarditis with antibiotics?

Answer 13

90% for native valve and 50% for prosthetic valve.

Question 14

What are indications for surgery in endocarditis?

Answer 14

severe regurgitation
large vegetation
persistent pyrexia despite antibiotics
progressive renal failure

Question 15

How do you treat aortic stenosis?

Answer 15

replace valve if severe

Question 16

How do you treat aortic regurgitation?

Answer 16

replace valve if severe, especially if LV dilated

Question 17

How do you treat mitral stenosis?

Answer 17

surgery if mitral valve area <1.5cm on echo

Question 18

How do you treat mitral regurgitation?

Answer 18

replace valve if severe. see blood flow reversal in pulmonary veins.

Question 19

How is cardiopulmonary bypass carried out?

Answer 19

blood drained from RA then returned to ascending aorta. pumped at constant pressure. anticoagulants (heparin) given too.

Question 20

What is the maximum time for cardiopulmonary bypass and why?

Answer 20

12hrs - too much cellular necrosis will have taken place for patient to survive

Question 21

What is cardiopulmonary bypass?

Answer 21

heart and lung function taken over so heart can be operated on

Question 22

What are common issues after cardiopulmonary bypass?

Answer 22

• normal coagulation of blood takes a few days to get back to normal. may cause excessive bleeding
• air-embolism is also risk - do valsalva maneuvre to eliminate risk.

Question 23

What are options for heart valve prosthesis/repair?

Answer 23

biological/pig valve
mechanical valve
mitral valve repair

Question 24

What are benefits and negatives with biological/pig valve prosthesis?

Answer 24

no warfarin required, wears out after 15yrs. for elderly but maybe <55’s

Question 25

What are benefits and negatives with mechanical prosthesis?

Answer 25

warfarin required for life. lasts 40+ years so given to <50’s.

Question 26

Whats better - mitral valve replacement or repair?

Answer 26

repair if total competence can be restored. otherwise replacement.