Ischaemic Heart Disease Flashcards
what are the presenting symptoms of Ischaemic Heart Disease (IHD)?
MI, angina pectoris, chronic ischaemic heart disease, sudden death
What are the causes of IHD?
- blood supply to heart is insufficient for its metabolic demand: coronary artery disease, reduced coronary artery perfusion- shock or aortic valve stenosis
- excessive demand: pressure overload due to hypertension and valve disease, volume overload due to valve disease
what are the main arteries where coronary atherosclerotic lesions occur?
- LAD
- left circumflex artery
- right coronary artery
what causes atheromatous coronary artery disease?
- progressive stenosis
- haemorrhage into plaque, evasion and eruption
- thrombosis
- emboli from inflamed aortic valve- endocarditis
- vasculitis
Define MI
area of ischaemia necrosis of the heart muscle caused by occlusion of coronary blood supply
what are some key causes of MI?
- coronary artery thrombosis
- haemorrhage into coronary plaque
- increase in demand in the presence of ischaemia
what areas are affected when any of the 3 coronary arteries commonly affected are occluded?
LAD- anterior wall of the left ventricle near apex, anterior portion of inter ventricular septum
RCA- inferior posterior wall of LV, posterior position of ventricular septum
LCX- lateral wall of LV not apex
Macroscopic changes 24-48 hrs after MI?
Pale oedematous muscle
Microscopic changes 24-48 hrs post MI?
oedema, neutrophil infiltration , necrosis myocytes
3-4 days post MI macroscopic changes?
yellow rubbery centre
haemorrhagic border
3-4 days post MI microscopic changes that occur?
obvious necrosis and inflammation
what are the macroscopic changes 1-3 weeks post MI?
pale thin infarcted area
1-3 weeks post MI what are the microscopic changes?
granulation tissue, progressive fibrosis
what are macroscopic features of MI 3-6 weeks post MI?
silvery scar becoming tough and white
what are the microscopic changes 3-6 weeks post MI?
dense fibrosis
what are the clinical features of MI?
-central crushing chest pain
features of heart failure
how can MI be diagnosed?
clinical history, ECG changes, blood markers- enzyme creatine kinase and proteins such as troponin
what complication of MI can occur in a few hours post MI?
sudden death
result of ventricular fibrillation
when do arrhythmias occur post MI?
abnormal electrical activity
in a few days
persisten pain can occur how long post MI? what is it?
12-hours to a few days
-progressive necrosis (extension)
how does angina result? how long after MI?
- ischaemia of non infarcted cardiac muscle
- immediate or delayed
what is variable when it occurs post KMI?
cardiac failure
ventricular dysfunction arrhythmias
MI leads to papillary muscle dysfunction and necrosis. what does this cause?
mitral incompetence
what can occur 2-4 days post MI?
pericarditis
inflammation of the pericardium producing a sharp chest pain
what can occur 3-5 days post MI?
cardiac rupture= weakening of the wall by necrosis
when can a mural thrombosis potentially occur as a result of MI?
week or more later
abnormal endothelial surface
what can occur 4 weeks or more post MI?
ventricular aneurysms
stretching of newly formed scar tissue
what are the two clinic0 pathological features of chronic ischaemic heart disease?
chronic angina
heart failure
describe the features of chronic angina
exercise induced pain
stable or unstable
sudden cardiac death due to arrhythmia
describe the features of heart failure
related to reduced myocardial function
widespread coronary atheroma
areas of fibrosis in myocardium
