Surgery in Valvular and IHD Flashcards
What are some causes of cardiac ischaemia?
Atherosclerosis Embolism Coronary thrombosis Aortic dissection Arteritides Congenital conditions
What are the clinical manifestations of IHD?
Angina MI Arrhythmias Chronic Heart Failure Sudden Cardiac Death
What are the two most dangerous manifestations of coronary artery disease
Left main stem stenosis
3 (Triple) vessel coronary artery disease
When might you use coronary artery bypass grafting in a patient?
In symptomatic patients
If they have poor prognosis (left main stem stenosis, triple vessel disease)
What is considered in determining a patient’s suitability for CABG surgery?
Adequate lung function Adequate mental function Adequate hepatic function Ascending aorta be healthy Distal coronary targets must be ok LV EF >20%
What vessels may be used in CABG?
Reversed saphenous vein
Internal mammary arteries
Radial arteries
What are some problems associated with sternotomy?
Wire infection
Painful wires
Sternal dehiscence
Sternal malunion
What are some typical post-op problems in CABG?
Cardiac tamponade
Death
Stroke
What is cardiac tamponade?
Pericardial fluid exerting pressure on the heart
Primary features:
- raised CVP, HR
- low BP
Secondary features:
- oliguria
- increased O2 requirements
- metabolic acidosis
Treatment
- chest reopening
What are the long-term outcomes post CABG?
50% have no further cardiac problems 10Y layer
Of the 50% who do, majority are minor issues, easily controlled with medication
5% may require repeat CABG
What are the valves mostly operated on? Does it vary in children?
Aortic and mitral in adults
All four with roughly equal frequency in children
What are some causes of valvular heart disease in adults?
Degenerative Congenital Infective Inflammatory LV or RV dilatation Trauma Neoplastic Paraneoplastic
What are the most common valve problems requiring surgery in Aberdeen?
Senile aortic valve stenosis (calcium deposition)
Bicuspid AS (congenital bicuspid aortic valve)
Degenerative MR
How is aortic stenosis differentiated from aortic sclerosis in terms of signs?
Loss of S2 in stenosis, no loss in sclerosis
When might surgery be recommended in mitral stenosis?
If MVA on echo is <1.5cm2
What is a cardiopulmonary bypass?
Developed clinically in 1950s Blood drained from RA and returned to ascending aorta Heart and lung function taken over by CPB machine Systemic anticoagulation required Induced hypothermia Non-pulsatile flow during CPB Max time 12 hours Max cardiac ischaemic time 6 hours
What factors decide the choice of heart valve prosthesis?
Biological valve
- no warfarin required but valve wears out after 15 years
Mechanical valve
- lifelong warfarin, but valve lasts >40 years
Mitral valve repair possible in many cases of degenerative MR
When complete valve competence is restored, repair is better than replacement for mitral.
What organisms are associated with Rheumatic Fever, and which with endocarditis?
Streptococcal infections are related to rheumatic fever
Strep viridans is the most common endocarditis (subacute)
Staph aureus second most common (acute)
Infected valve may have been diseased beforehand or may have been normal
In endocarditis, how does outcome vary in native vs prosthetic valves?
90% chance of cure with antibiotics alone in native valve
Only 50% in prosthetic
Chance of cure much higher with strep viridans than SA
What are the indications for surgery in endocarditis?
Severe valvular regurgitation
Large vegetations
Persistent pyrexia
Progressive renal failure
Antibiotics are given IV for 6 weeks post-op
