Cardiac Surgery

Question 1

List the differences between a mechanical and prosthetic valve replacement

Answer 1

Mechanical
- for those <70
- have increased risk of thromboembolism so require INR of 2-3 with warfarin
Bio-prosthetic
- for those >70 or contraindication to anticoagulation
- decreased risk of thromboembolism but does not last as long
- cannot use with dialysis

Question 2

List the DeBakey and Stanford classification of aortic dissection

Answer 2

DeBakey:
- 1 involvement of ascending and descending
- 2 involvement of ascending aorta only
- 3A involvement of thoracic aorta
- 3B involvement of abdominal aorta
Stanford
- A is Debakey 1 and 2
- B is Debakey 3

Question 3

Discuss the indications for coronary artery bypass grafting

Answer 3

• > =2 vessel disease in diabetic patients
• 3 vessel disease especially when LVEF <50%
• 2 vessel disease with significant proximal left anterior descending disease
• 1 or 2 vessel disease without significamt LAD disease who survived sudden cardiac death
• significant left main coronary disease

Question 4

Discuss post-pericardiotomy syndrome

Answer 4

• onset within weeks to 3 months post-operatively
• pleuritic chest pain
• pericardial friction rub
• ECG: PR depression and diffuse ST elevation
• treat with high dose aspirin or NSAID

Question 5

Discuss complication of myocardial infarction

Answer 5

Cardiogenic shock:
- decrease in CO leading to shock and acute congestive heart failure
- emergency CABG
Free Wall Rupture
- rupture of ventricle or atrial wall
- acute tamponade
- surgical closure
Papillary muscle rupture
- posterior/inferior MI affect papillary muscle which lead to acute mitral regurgitation
- pan-systolic murmur and acute congestive heart failure
- mitral valve replacement
Ventricle Septal Rupture
- anterior and inferior infarct
- pan-systolic murmur
- surgical repair
Ventricular aneurysm
- dyskinetic movement leading to aneurysm-> clot 
- acute congestive heart failure
- surgical resection of aneurysm