Cardiothoracics Flashcards
What is often used as a graft in CABG?
Saphenous vein
What is the circumflex artery?
- Originates from LCA
- Supplies the LA + posterior LV
What is the LAD artery?
- From LCA
- Supplies the anterior LV + anterior septum
What is the RCA?
Supplies the RA, RV, inferior LV and posterior septum
What happens during a CABG?
- Cardiopulmonary bypass
- Cardioplegia-> stop heart beating
- Graft inserted-> usually saphenous vein, free graft (whole vessel put somewhere new)
How does CP bypass work?
- Machine takes blood from VC/RA
- Adds O2 and removes CO2
- Adds heparin to prevent clotting
- Blood back to ascending aorta
What is cardioplegia?
- During CABG-> stops heart beating
- Use high K+ solution into circulation-> spontaneously starts when stop infusion
- In arrythmias-> CV or temporary pacing
What are the complications of CABG?
- Slow recovery-> resume normal activity in 3 months
- Death
- Stroke
- Infection
- AKI
- Cognitive impairment
- MI
- AF
- Vein can stenose over time (intimal hyperplasia)-> arterial less affected so better
What are some congenital cardiac conditions?
- ASD
- VSD
- Coarctation of aorta
- PDA
- Tetralogy of Fallot
- Ebstein’s anomaly
- Transposition of great arteries
What is cyanotic heart disease?
- When deoxygenated blood enters the systemic circulation
- Due to bypassing the pulmonary circulation + lungs
- Right to left shunt
What is acyanotic heart disease?
- Left to right shunt-> left heart pressure higher than right
- Can become right to left if really bad-> Einsenmenger’s
- EG ASD, VSD, PDA
What is Eisenmenger syndrome?
- Pulmonary pressure becomes higher than systemic
- Blood flows from right heart to left heart and causes cyanosis
What are some complications of congenital heart disease?
- Heart failure
- Arrhythmias
- Endocarditis
- Stroke
- Pulmonary HTN
- Eisenmenger
- Pregnancy complications
What is an atrial septal defect?
Hole between 2 atria causing blood flow between
What are the types/causes of atrial septal defect?
- Patent foramen ovale-> not always classified as ASD
- Ostium secondum-> septum secondum doesn’t close
- Ostium primum-> septum primum fails to close + causes AVSD
What is the pathophysiology of atrial septal defect?
- Acyanotic-> LA to RA shunt
- Blood oxygenated-> flows through pulmonary vessels + lungs
- Increased flow-> right overload + strain-> pulmonary HTN + RHF
- Can lead to Eisenmenger-> shunt reverses
How does atrial septal defect present?
- Asymptomatic + pick up on antenatal scans
- Older-> dyspnoea, stroke, DVT, AF, atrial flutter
- Murmur-> mid-diastolic, crescendo-decrescendo, loudest at left sternal border
- Fixed split second heart sound-> blood in RV that has to empty before pulmonary valve closes
How is atrial septal defect managed?
- Watch + wait if small
- Surgery-> percutaneous transvenous catheter closure or open
- Anticoagulants-> reduce stroke risk
What is ventricular septal defect?
- Hole in septum between ventricles
- Causes left to right shunt-> can switch if severe
What is ventricular septal defect associated with?
- In isolation
- Down’s
- Turner’s
- After MI-> ischaemia
How does ventricular septal defect present?
- Asymptomatic + pick up on scans
- Pansystolic murmur-> left lower sternal border at IC spaces 3 + 4
What causes a pansystolic murmur?
- VSD
- Mitral regurgitation
- Tricuspid regurgitation
What causes a mid-diastolic murmur?
-Atrial septal defect
How is ventricular septal defect managed?
- Surgical-> transvenous catheter closure or open heart
- Antibiotic prophylaxis before surgery-> for IE
What is coarctation of the aorta?
Narrowing of aortic arch-> usually around ductus ateriosus
What is coarctation of the aorta associated with?
- Turner’s syndrome
- Recurrence after treatment
What is the pathophysiology of coarctation of the aorta?
- Narrowing of arch
- Reduced pressure of blood flowing to distal arteries
- Increased pressure proximally-> heart + three branches
What are the three artery branches on the aortic arch?
- Brachiocephalic
- Left common carotid
- Left subclavian
How does coarctation of the aorta present?
- Often HTN in adulthood-> 1st sign
- Systolic murmur-> below left clavicle + scapula
- 4 limb BP-> high from arteries with supply before narrowing + low in those after
- LV heave
- Underdeveloped left arm-> reduced left subclavian artery flow
- Underdeveloped legs
- CT angiography shows
How is coarctation of the aorta managed?
- CT angiography can confirm
- None if symptom free
- Percutaneous balloon angioplasty +/- stent
- Open heart
- Medical management HTN
What is pericardial effusion?
- Excess fluid in pericardial sac
- Acute or chronic
- Transudate (low protein) or exudate (inflammation)
- Can be blood, pus, gas etc
What is the pathophysiology of pericardial effusion?
- Pericardium/pericardial sac surrounds heart
- Potential space-> usually <50ml
- Effusion-> fills space + pressure on heart
- Harder to expand when filling (diastole)
- Tamponade-> raised intra-pericardial pressure + affects heart function
What is the function of the pericardium?
- <50ml fluid
- Separates heart from mediastinum
- Lubrication-> allow heart to beat without friction
- Is a potential space-> usually touch
What is cardiac tamponade?
- pericardial effusion large enough to affect heart function
- reduces filling + cardiac output
- emergency + needs drainage
What causes transudative pericardial effusion?
Transudative (low protein)-> CHF or pulmonary HTN (increased venous pressure + reduced drainage)
What causes exudative pericardial effusion?
- Infection-> TB, HIV
- Autoimmune-> SLE, RA
- Injury-> MI, surgery
- Uraemia-> secondary to renal impairment
- Cancer
- Medications-> MTX
What can cause pericardial effusion due to bleed?
- Rupture of heart or aorta from MI
- Trauma
- Type A aortic dissection
How does pericardial effusion present?
- Can be slow or quick
- Chest pain, SOB, fullness feeling, orthopnoea
- Worsens + press on structures
- Hiccups-> phrenic nerve
- Dysphagia-> oeseophagus
- Hoarse voice-> recurrent laryngeal
- Quiet heart on auscultation
- Pulsus paraxodus
- Hypotension
- Raised JVP
- Pericardial rub-> infection
How is pericardial effusion diagnosed?
- Echo-> size + function
- Fluid analysis-> protein, bacterial, PCR, cytology, tumour markers
How is pericardial effusion managed?
- Treat underlying cause + drain
- Inflammatory-> NSAIDs, colchicine, steroids
- Needle pericardiocentesis-> US guided
- Surgical-> pericardial window
What is thoracic aortic aneurysm?
- Dilation of thoracic aorta
- Ascending-> 4.5cm<
- Descending-> 3.5cm
Where does blood collect in a false aortic aneurysm?
- Inner intima + media layers ruptured
- Within adventitia-> outer layer
What is the cause of thoracic aortic aneurysm?
- After surgery
- RTA
- Infection
Where does blood collect in a true aortic aneurysm?
3 layers are intact but dilated so within vessel
How does thoracic aortic aneurysm present?
- Asymptomatic
- Chest pain
- Back pain
- Trachea/left bronchus compression-> cough, SOB, stridor
- Hiccups
- Dysphagia
- Hoarse voice
How is thoracic aortic aneurysm diagnosed?
- Echo
- CT or MRI angiogram
How is thoracic aortic aneurysm managed?
- Risk factor reduction
- Surveillance
- TEVAR
- Open surgery
What are the complications of thoracic aortic aneurysm?
- Aortic dissection
- Ruptured aneurysm
- Aortic regurgitation
What are the symptoms of ruptured thoracic aortic aneurysm?
- Haematemesis
- Haemoptysis
- Tamponade
- Severe chest/back pain
- Haemodynamic instability
- Collapse
- Death
How is ruptured thoracic aortic aneurysm managed?
Emergency replacement of aorta with graft
What are some indications for heart transplant?
- CHF
- IHD
- Cardiomyopathy
- Congenital heart disease
What are some indications for lung transplant?
- COPD
- Pulmonary fibrosis
- CF
- Pulmonary HTN
When is heart or lung transplant done?
Within 6 hours of donor death
How is heart or lung transplant performed?
- Donor organ given cold ischaemic time-> cooled to reduce damage
- CP bypass
- Implant
- Reperfused + warmed
What is required after heart or lung transplant?
Lifelong immunosuppressant-> avoid rejection
What are some side effects of immunosuppressants?
- Diabetes
- Osteoporosis
- Cushing’s
- Infections
- SKin cancer
- Non-Hodgkin lymphoma
What is a complication of heart transplant?
Cardiac allograft vasculopathy-> narrowing of CAs in donor heart
What are some complications of lung transplant?
- Primary graft dysfunction-> oedema, damage, hypoxia
- Bronchiolitis obliterans syndrome
- Dehiscence of bronchial anastamosis
