Cardiothoracics Flashcards
Risks of cardiopulmonary by-pass
Systemic inflammatory response
Cerebral damage (1%): intracerebral bleeding, embolisation of microbubbles or arterial debris, or inadequate cerebral perfusion
Bleeding – multifactorial causes including hypothermia,
platelet dysfunction, CPB and pharmacological (aspirin,
clopidogrel)
Low cardiac output – poor myocardial protection, previous poor left ventricular (LV) function
Arrhythmias – atrial fibrillation occurs in up to 40%
Infection – wound, respiratory
Short-term memory impairment.
Thallium isotope scan
Areas of low uptake –> impaired myocardial perfusion
Graft for coronary bypass
Internal thoracic artery
Pedicled graft, left attached to the subclavian artery proximally
Common combination is to use the left ITA for the left anterior descending artery and vein grafts for the other vessels
Mitral valve replacement
Chronic
-Ischaemia causes papillary muscle fibrosis due to CAD
-Elective procedure usually concurrent with coronary artery bypass
Acute
-Acute MI may cause papillary muscle rupture –> gross regurgitation
–> Flash pulmonary oedema
–> Ventillation
Requires emergency replacement carryign 15-40% mortality
Indications for aortic valve replacement
-Symptomatic patients with severe AS
-Patients with severe AS undergoing an concurrent procedure such as CABG or valve replacement
-Symptomatic patients with sevre AR regardless of LVEF
-Severe AR with reduced LVEF
-Sevre AR underoing concurrent procedure such as CABG or valve replacement
Mitral valve (MV) surgery (repair if possible) is indicated in patients with symptomatic moderate or severe mitral stenosis
MV surgery is recommended for the symptomatic patient with acute severe mitral regurgitation (MR).
MV surgery is beneficial for patients with chronic severe MR
Post-myocardial ventricular septal defect
Necrosis of the intraventricular septum
Left-to-right shunt
Increases work-load of right heart
Sudden severe SOB 3-8 days post MI
+ new pan-systolic murmur
Surgical repair difficult as spetum is ischaemic and LVEF poor due to MI
May need mechanical support of their ventricle with an intraaortic balloon pump
Valvular gradient of severe aortic stenosis
60mmHg
Echo findings of severe mitral stenosis
Area of < 1cm2 = severe
Also likely to have atrial enlargement, pulmonary hypertension
Subsequently causing right ventricular hypertrophy
Entry points for aortic dissection
Just above the aortic valve
Immediately beyond the left subclavian artery
Complications of aortic dissection
Rupture
Ischaemia due to compression of branches of aorta
Aortic regurgitation
Aorto-annulo ectasia
Flask-shape aneurysmal diliatation of ascending aorta or aortic root
Associated with connective tissue disorders, most commonly Marfan’s disease.
Indomethacin infusion
Closure of patent ductus arteriosus in premature neonates
Most common cause of cyanotic congenital heart disease
Tetralogy of fallot
-Overriding aorta
-Ventricular septal defect
-Pulmonary stenosis
-Right ventricular hypertrophy
Tetralogy of fallot
High ventricular septal defect
Aorta that overlies the intraventricular septum (receiving blood from both ventricles)
Right ventricular outflow obstruction - pulmonary stenosis
Right ventricular hypertrophy
RIGHT –> LEFT shunt
Mx:
-Patch intraventricular septum
-Resecting muscle bands contributing to right ventricle outflow obstruction
-Patching pulmonary valve annulus
Indications for surgical interventions for lung cancer
Stage I and II non-small cell: aim for surgical resection with curative intent
Patients with poor LVEF or unstable angina are not suitable for pulmonary resection
