Acute Coronary Syndromes Flashcards
2 pathology processes of acute coronary syndromes
- blood vessel narrowing
- blood vessel occlusion
what is felt if blood vessel narrows?
- inadequate oxygen delivery for tissue needs
- cramp’ in affected tissue/muscle
- no residual deficit at first
what is felt if blood vessel occludes?
- no oxygen delivery - tissue death
- more severe pain
- loss of function of tissue
how will muscle metabolise when there is insufficient blood flow?
anaerobically
Stop doing exercise and allow requirements to drop
- Make up lactic acid debt and return to normal
what can happen over time if there is a lactic acid build up?
damage (10+ years)
- hypoxia leading to less effective cardiac muscle
what is key in treatment of acute coronary syndromes?
early effective treatment
what are 3 points in ACS diagnosis?
- history
- ECG findings
- biomarkers
what should be gathered from history taking for ACS?
- what can the patient tell you about their issues
- how the patient feels conditions differently
helpful information but not exclusive
what are the 2 classes of ECG findings in ACS diagnosis?
- STEMI
- NSTEMI
STEMI ECG finding
ST segment elevation myocardial infarction
NSTEMI ECG finding
no ST segment elevation myocardial infarction
biomarkers in ACS diagnosis
- released from damaged cells
- released into blood circulation
- increase with time and tissue damage
factors that influence artherosclerosis occurring
genetic mainly
can be worsened by lifestyle factors
- family history is good to assess
where do coronary arteries come away from?
the aorta, aortic valves cover the openings to coronary arteries
when does blood flow into coronary arteries?
during diastole
what causes a significant increase in inadequate blood flow to coronary arteries?
increased heart rate as shorter diastole
what are the 3 main coronary arteries?
- right
- left
- circumflex
what happens if there is a blockage in one of the coronary arteries?
can lead to low oxygen supply to part of cardiac muscle
- can be lethal
poorly designed
what is angina pectoris?
reversible ischaemia of heart muscle
- narrowing of one or more coronary arteries
how to differentiate ‘classical’ angina from ‘unstable’ angina?
‘classical’ angina gets worse with exercise
‘unstable’ angina has symptoms at rest with no biomarkers
what is the symptom of angina? (both classical and unstable)
‘central crushing chest pain’
- radiation to arm, back, jaw possible
‘classical’ angina symptoms
- No pain at rest
- pain with certain level of exertion (worse with cold weather/emotion)
- pain relieved by rest (Use up all spare muscle around heart muscle; Get chest pain; Stop pain dissipates)
- patient lives within limits of tolerance (avoids generating pain)
- gradual deterioration
- As disease gets worse exercise tolerance gets less and less
Easily reproduced defined change
what are ‘classical’ angina signs?
Often none
- They don’t push themselves far enough to generate pain
Occasionally hyperdynamic circulation - anaemia - hyperthyroidism - hypovolaemia (less O2 in blood supply worsens these)
4 types of investigations used for angina
- ECG (resting and exercise)
- angiography
- echocardiography
- isotope studies (function assessment)
eliminate other diseases (thyroid; anaemia; valve)
what does a resting and exercise ECG tell you about angina?
shows area of myocardial ischaemia
at rest ECG should be normal and then with gradual increased exercise can see change (increase pace and inclination of treadmill)
- can see changes happening before pain in chest generated
infarction causes ECG changes all the time
what does an angiography tell you about angina?
dye injected to see if there is a narrowing
what do isotope studies tell you about angina?
function assessment
radioisotope in cardiac chambers and assess how efficient heart is at pumping out
what is an ischaemic episode on an ECG?
ST depression
what can an agiogram show you?
narrowing of coronary artery, potentially coronary artery blockage
- if narrowing blood flow will be restricted but not blocked - dye can still pass beyond narrowing
4 methods of angina treatment
- reduce oxygen demands to the heart
- increase oxygen delivery to the tissues
- dilate blocked/narrowed vessels
- bypass blocked/narrowed vessels
surgical, drug and non-drug