Cardiothoracic Surgery Flashcards
(42 cards)
Which of the following is not a risk factor in atherosclerosis?
A. Older age
B. Smoking
C. Sleep
D. Alcohol
C. Sleep
Outline the pathophysiological process of atherosclerosis.
Endothelial damage of the tunica intima in combination with elevated lipid levels result in accumulation of LDL in the tunica intima. Macrophages uptake LDL to become lipid-laden foam cells. An inflammatory response is mediated by cytokines which result in Ox-LDL, unable to return to circulation.
Fibrosis and sclerosis may occur which strengthens the atheroma with a fibrous cap.
Increased TNF-a may result in plaque destabilisation and necrosis which leads to plaque rupture.
What is the management for CAD?
Supportive: RF modification; referral to cardiologist
+
Medical: Antiplatelets + Beta blockers + Statins
± Surgery
- PCI with coronary angioplasty
- Coronary artery bypass graft
What is the term for the process of stopping a heartbeat during a CABG?
Cardioplegia using a EC solution with high concentration of electrolytes
What two types of grafts may be used in a CABG?
How do they differ.
Free graft (section entirely separated from original connections before reattaching in new site)
Pedicled graft (graft origin remains in tact and re-routed)
Why may vein grafts have a tendency to become stenosed?
Intimal hyperplasia whereby tunica intima layer becomes thickened due to increased pressure.
What are the complications of a CABG?
Death (2-3%) Stroke (1-5%) Infection AKI Cognitive impairment MI AF
What is the INR range required for those with a mechanical valve?
2.5-3.5
What types of mechanical heart valves exist?
Tilting disc
St Jude (bileaflet valves) - lowest thrombus formation risk
What are the major complications of mechanical heart valves?
Thrombus formation
Infective endocarditis
Haemolysis causing anaemia
What are the types of ASD?
Patent foramen ovale
Ostium secondum
Ostium primum
How is an ASD best heard?
Mid-systolic, crescendo-decrescendo murmur loudest at upper left sternal border with fixed split second heart sound
No change with inspiration and expiration
Why does a fixed split second heart sound occur in ASD?
No change with inspiration and expiration as increased blood flow from L atrium into R atrium across ASD. The increasing volume that the RV most empty before the pulmonary valve ca close thus does not vary with respiration
How may a VSD present?
Pan-systolic murmur more prominent at left lower sternal border in 3/4th ICS
How is a VSD managed?
Surgery: Transvenous catheter closure; Open surgery
How may CoA present?
Systolic murmur infraclavicular; discrepancy of blood pressure in upper cf lower limbs
LV heave
How may a CoA be managed?
Percutaneous balloon angioplasty
Open surgical repair
What are the causes of pericardial effusion?
Infection Autoimmune conditions Injury Uremia Cancer Medications
How may you manage a pericardial effusion?
Tx underlying cause
+
Drainage of effusion: Needle pericardiocentesis; Surgical drainage
A pericardial window may be used to create a fistula allowing fluid to drain the pericardial cavity into pleural or peritoneal cavity
what is the difference between a true and false aneurysm?
True = all 3 layers of aorta
False = 2/3 layers, adventitia contains the blood
How may a thoracic aortic aneurysm present?
Chest or back pain
Trachea or left bronchus compression may cause cough, shortness of breath and stridor
Phrenic nerve compression may cause hiccups
Oesophageal compression may cause dysphagia (difficulty swallowing food)
Recurrent laryngeal nerve compression may cause a hoarse voice
Which type of lung cancer is related to PTHrP secretion?
SCC
Which lung cancer is related to increased ß-hCG secretion?
Large cell carcinoma
Which lung cancer is the most common in non-smokers?
AC
