What characterises chronic stable angina? (4)
what advice can be given when pain arises from chronic stable angina?
whats is ACS?
What disease do ACS comprise?
= Acute Coronary Syndrome
= any acute presentation of coronary artery disease;
(covers a spectrum of diseases)
what are the 2 types of acute myocardial infarction?
1) ST elevation MI
(STEMI)
2) Non-ST elevation MI (NSTEMI)
what are the 5 pathogenetic stages of acute coronary syndrome?
1) normal
2) fatty streaks
3) atherosclerotic plaques
4) fibrous plaque
5) plaque rupture/fissure & thrombosis
what are the characteristics of acute coronary syndrome? (4)
- unstable angina/MI
what is the main pathogenetic factor that occurs in ACS?
= spontaneous plaque rupturing
what factors affect plaque rupture/fissure?
what does vascular damage expose?
what happens in response to vascular injury?
= PLATELET recruitment and adhesion at site of injury forming a monolayer.
when platelets undergo degranulation what do they release and generate?
Release = ADP & other activators
Generate = thromboxane A2 via cycloxyganse
what binds to platelet receptors which consequently results in platelet activation and hence platelet aggregation?
what do these activated platelets express and trigger?
ADH binds to platelet receptors.
express = adhesion receptors for leukocytes.
trigger = inflammatory cascade
what is platelet aggregation?
= the clumping together of platelets in the blood which eventually leads to the formation of a thrombus.
what 4 things in a history is indicative of a ST elevation MI?
1) severe crushing central chest pain
2) radiating to jaws, arms, especially left
3) similar to angina but more severe, prolonger & NOT received by GTN
4) associated with sweating nausea & vomiting
describe the differences between angina and MI in terms of duration, onset, severity, GTN and associate symptoms.
ANGINA;
MI;
what changes would be seen in an ECG during an acute STEMI?
1) ST elevation
- more than 1mm elevation in 2adjacent limb leads
or
- more than 2mm elevation in 2 continuous pre-cordial leads
3) new onset bundle branch block (BBB)
3) T wave inversion
4) Q wave
where is ST elevation seen in INFERIOR MI?
Leads II, III, aVF
where is ST elevation seen in anterior MI?
V1-V6
specifically, where is ST elevation seen in anteroSEPTAL MI?
V1-V4
specifically, where is ST elevation seen in anteroLATERAL MI?
Leads I, aVL, V1-6
what 2 cardiac enzymes could be used to diagnose an STEMI?
1) CK (creatinine kinase)
- peaks in 24hours but is non-specific
2) Tn (troponin)
- highly specific for cardiac muscle damage
- detecting tiny amounts of MI necrosis
what 2 anti-platelet drugs should be given to treat STEMI?
1) aspirin, 300mg
2) clopidogrel, 300mg
what are 3 indications for repercussion therapy (thrombolysis or PCI)?
1) chest pain suggestive of acute MI
- more than 20minutes less than 12hours
2) ECG changes
- acute ST elevation
- new LBBB
3) no contraindications
what are 3 risks for thrombolytic therapy?
1) failure to re-perfuse
2) haemorrhage
- minor
- major
- intra-cranial haemorrhage
3) hyper-sensitivity