ischaemic heart disease and valvular heart disease Flashcards
what are some of the causes of cardiac ischaemia?
Atherosclerosis (most common)
Embolism
Coronary thrombosis
Aortic dissection (Type A is the dangerous one because it is in the ascending aorta) and Type B)
Arteritides (means inflammation of the arteries)
Congenital
what are the clinical manifestations of ischaemic heart disease?
Angina
MI
Arrythmias (including very dangerous ones such as ventricular fibrillation and tachycardia), it is possible to get AF from ICH (anything which causes enlargement of heart will cause AF)
Chronic heart failure (particularly in diabetics because nerves affected so can’t feel angina)
Sudden death
what are the 2 dangerous patterns of CAD?
left main stem stenosis - occurs in LM coronary artery before it gives rise to left anterior descending and circumflex arteries
3 vessel coronary artery disease (when they all narrow)
what are the 2 indications for CAD bypass grafting?
symptomatic (any CAD pattern) - can cause angina and make patients life discomfortable but not life threatening
prognostic - life threatening one (LMSS, 3 vessel CAD)
what must we take into consideration when selecting
Adequate lung function
Adequate mental function
Adequate hepatic function
Ascending aorta OK
Distal coronary targets OK
LV EF > 20%
what are the primary and secondary features of cardiac tamponade following surgery?
Primary features – Raised CVP, raised heart rate (most important), low BP
Secondary features – Oliguria, increased oxygen requirements, metabolic acidosis
Treatment – chest re-opening
what are some of the causes of valvular heart disease?
Degenerative (such as degenerative aortic valve disease which causes AS, refer to the PowerPoint slide)
Congenital (most common is bicuspid aortic valve stenosis)
Infective
Inflammatory
LV or RV dilatation
Trauma (such as stab wound)
Neoplastic
Paraneoplastic
if enough rheumatic attacks happen, what can this cause?
chronic rheumatic heart disease
results in gradually progressive mitral valve degeneration (most commonly) but also AV deg.
what is endocarditis and what are the common organisms that give rise to it?
Inflammation of the inner lining of the heart chambers and valves. Usually caused by bacterial infection
Strep viridans the commonest organism – gives rise to subacute bacterial endocarditis
Staph aureus the second commonest organism – gives rise to acute bacterial endocarditis
Infected heart
what is the difference in cure with native valve endocarditis and prosthetic valve endocarditis?
NVE - 90% chance of cure with antibiotics alone
PVE – 50% chance of cure with antibiotics alone
Chances of cure much higher with strep viridans endocarditis than with staph aureus
Strep viridans is more vulnerable to penicillin so it is cured easier
when should we provide surgery for endocarditis?
Severe valvular regurgitation (heart failure not responding to meds)
Large vegetations (may break free and embolise)
Persistent pyrexia
Progressive renal failure
Antibiotics are given IV for 6 weeks post-operatively
what is severe MR associated with in terms of auscultation and changes to the heart?
loud murmur
LV and LA dilatation, onset of AF, and pulmonary hypertensionn
what is severe MR associated with on an echo scan?
systolic blood flow reversal in pulmonary veins
so severe MR if the blood flow goes back up the pulmonary veins from the left atrium
describe cardiopulmonary bypass?
drains blood from RA and returns it to ascending aorta
takes over heart and lung function
cools blood to induce hypothermia to reduce basal metabolic rate (adds protection to brain post operatively)
max time for CPB it is 12 hours
why is warfarin given to patients with prosthetic valves?
Patients with mechanical heart valves have a risk of thrombosis on the valve and subsequent embolism. Blood flows at high shear stress around the valve, which activates platelets and local coagulation.
