Flashcards in Ischaemic heart disease and valvular heart disease - surgeon approach Deck (33):
What are causes of cardiac ischaemia?
- Coronary thrombosis
- Aortic dissection
Manifestations of ischaemic heart disease
- Chronic heart failure
- Sudden death
Dangerous patterns for coronary artery disease
- Left main stem stenosis
3 vessel coronary artery disease
Indications for coronary artery bypass grafting
- Symptomatic (any CAD pattern)
- Prognostic (LMSS, 3VDx)
Features required for selection of patients for CABG (coronary artery bypass grafting)
- Adequate lung function
- Adequate mental function
- Adequate hepatic function
- Ascending aorta OK
- Distal coronary targets OK
- LV EF>20%
Conduits for CABG
- Reversed saphenous vein
- Internal mammary arteries
- Radial arteries
What is median sternotomy?
It is a type of surgical procedure in which a vertical inline incision is made along the sternum, after which the sternum itself is divided.
- This procedure provides access to the heart and lungs.
What are sternotomy related problems?
- Wire infection
- Painful wires
- Sternal dehiscence
- Sternal malunion
Post-operation problems in cardiac surgery
- Cardiac tamponade
Features of cardiac tamponade following cardiac surgery
- Primary features: raised CVP, raised heart rate, low BP
- Secondary features: oliguria, increased oxygen requirements, metabolic acidosis
Treatment for cardiac tamponade
Cardiac surgery for valvular heart disease in adults and children
Adult cardiac surgery- mainly aortic and mitral valve surgery.
Paediatric cardiac surgery - all four heart valves operated with roughly equal frequency.
Causes of valvular heart disease in adults
- LV or RV dilatation
What are the 3 commonest valve problems requiring cardiac surgery in Aberdeen?
- Senile Tricuspid AS
- Bicuspid AS
- Degenerative MR
Features of Rheumatic fever
- A relapsing illness
- Related to streptococcal infections
- ASO titre (type of blood test)
- The hallmark pathology is pancarditis
- Skin and joint manifestations are usual
- Syndenham's chorea/ St Vitus' Dance
- Treated with aspirin and bed rest
Primary prevention of rheumatic fever
Primary prevention of acute rheumatic fever requires adequate antibiotic treatment of streptococcal throat infections
Features of chronic rheumatic heart disease
- Gradually progressive MVDx +/- AVDx
- Worldwide is the commonest heart problem
- Worldwide is a major cause of death in pregnancy
Which organisms give rise to Endocarditis?
- Strep viridans is the commonest organism: gives rise to subacute bacterial endocarditis
- Staph aureus is the second commonest organism: gives rise to acute bacterial endocarditis
Infected heart valve may have been diseased beforehand or may have been normal
Chances of cure for NVE (native valve endocarditis) and PVE (prosthetic valve endocarditis)
NVE - 90% chance of cure with antibiotics alone
PVE - 50% chance of cure with antibiotics alone
Which organism gives a higher cure chance?
Chances of cure much higher with strep viridans endocarditis than with staph aureus
What are indications for surgery in endocarditis?
- Severe valvular regurgitation
- Large vegetations
- Persistent pyrexia
- Progressive renal failure
How long are antibiotics given for post-operatively for endocarditis?
Antibiotics are given IV for 6 weeks post-operatively
Features of aortic stenosis
- Typically presents as heart failure, angina, syncopal episodes or as an asymptomatic incidental finding.
- The murmur is usually easily heard.
- Loss of aortic S2 differentiates it from aortic sclerosis.
- ECG/ECHO- LVH.AV gradient > 50mmHg
- AVR recommended for severe aortic stenosis.
Features of mitral stenosis
- Murmur is usually difficult to hear
- If easily heard then the stenosis is severe
- May have to exercise the patient to hear the murmur
- Presystolic accentuation may be present
- Surgery recommended if MVA on ECHO is < 1.5cm2
Features of aortic regurgitation
- Typically presents as heart failure, angina or as an asymptomatic incidental finding
- The murmur is usually difficult to hear
- The louder the murmur the more severe the aortic regurgitation
What is recommended for severe aortic regurgitation?
Aortic valve replacement recommended for severe aortic regurgitation especially with left ventricular dilatation.
- In severe AR the entire LV is filled with contrast after one diastolic interval during aortography
Features of Mitral regurgitation
- Murmur is usually easy to hear
- If murmur is loud, MR is usually severe.
- Severe MR on ECHO characterised by systolic blood flow reversal in the pulmonary veins.
What is severe Mitral regurgitation associated with and what is recommended for it?
It is associated with LV and LA dilatation, onset of AF and pulmonary hypertension.
MVR recommended on the basis of severe MR being present.
How is a Cardiopulmonary Bypass carried out?
- Blood drained from the RA and returned to the ascending aorta.
- Heart and lung function taken over by CPB machine.
- Systemic anticoagulation necessary
- Induced hypothermia
- Non-pulsatile flow during CPB.
What is the maximum cardiopulmonary bypass time limit?
- Maximum cardiac ischaemic time is 6 hours.
What are common problems in cardiopulmonary bypass?
- Air embolism
What is coagulopathy?
A condition in which the blood's ability to coagulate (form clots) is impaired.
- This condition can cause a tendency toward prolonged or excessive bleeding (bleeding diathesis).