angina and MI Flashcards
what is stable angina
fixed stenosis due to atheroma, pain on exercise relieved by GTN spray
what are acute coronary syndromes
cause unstable angina and MI’s, complelte or partial occlusion of coronary arteries, supply led ischaemia.
when do plaques become particularly dangerous
when they rupture
what factors favour plaque rupture
thin fibrous cap, sudden changes in pressure, lipid content, thickness of plaque
what is the platelet cascade in thromboses
3 steps, adhesion, activation and aggregation. Plaque ruptures and platelets adhere to damages site via vWF. They then become activated and aggregate. this causes a blockage.
what can stable angina develop into and what are the differences
unstable angina, pain at rest and lying down. GTN becomes less effective
how does unstable angina differ from an MI
MI lasts over 30mins, no GTN relief
what are the 2 types of MI
ST elevation MI (STEMI), non-ST elevation MI (NSTEMI)
what are the symptoms of an MI
sweating, lasts longer than 30 mins, crushing central chest pain that can radiate to left arm. (full occlusion)
what does a STEMI show on an ECG
elevated ST, or t wave inversion (ischaemia)
what must the ST elevation show
1mm STE in 2 or more adjacent limb leads or 2mm in 2 or more precordial leads
what leads show inferior MI and which artery is occluded
II, III, aVF, right coronary
what leads show anteroseptal
V1-V4, LAD
which leads show anterolaterl MI
V4-6 LAD or left circuflex
what 2 proteins can be used for diagnosing an MI
CK enzyme and troponin
which protein is better and why
troponin, specific to cardiac cells and CK peak production is 24 hours after MI
what is immediate treatment of MI
morphine, oxygen, nitrate (GTN) if BP>90. Aspirin and clopidogrel
what is the window of time needed for a PCI
90 mins
what should be done if PCI can’t be done in 90 mins
thrombolysis
what is dressler’s syndrome
post MI syndrome, can cause pericarditis, pericardial effusions
what are troponin levels in normal people
negligible
what can be done to prevent further MI’s
angioplasty and leave stent
can ECGs be normal in MI’s
yes, if acute or NSTEMI
what are some contraindications to thrombolysis
trauma, haemorrhage, recent surgery, stroke, hypertension
what artery if often occluded in MI
LAD artery
what are some coronary revascularisation procedures
coronary arterial bypass grafting (CABG), angioplasty (PCI)
what is CABG
3 vessels on bypass (from radial artery and saphenous vein), attach distal to blockage
what is involved in PCI
put patient on antocoag and antiplatelets. balloon stent
what is better CABG or PCI
CABG
what is the treatment for angina
1) GTN, 2) CBB or beta blockers 3) potassium channel activator nicorandil 4) long term nitrate ISMN
which chest leads show posterior
V1-V2 = left circumflex
what prophylaxis treatment can be given in MI’s
aspirin, clop, ACE/ARB, statins
