206 MI Flashcards
What cause the myocardial damage in an NSTEMI?
Prolonged myocardial ischaemia
Name the cardiac enzymes measured when investigating ACS
CK
Troponin
AST (aspartate aminotransferase)
LDH (lactic dehydrogenase)
What is the most likely diagnosis if the cardiac enzymes are not raised after a ?ACS ?
Unstable angina
What is the initial treatment of ACS?
IV access Streptokinase 1.5M units per 100ml NaCl (0.9%) Analgesia - diamorphine 2.5mg Aspirin 300mg Bloods - incl cardiac enzymes ECG
What is a type A aortic dissection?
Dissection in the root within the pericardium - chambers - requires surgery
What is a type B aortic dissection?
Dissection in the arch and beyond - manage the BP here
What are the symptoms of a pericardial effusion?
Flu-like symptoms, chest pain, SOB
Name 4 DDx for chest pain (6 listed)
- Acute aortic dissection
- MI
- Acute pericarditis
- Acute PE
- PnTx
- Referred pain
What is the treatment for a STEMI?
Bolus thrombolytics
Cath lab for PCI (give clopidogrel + abciximab)
What are the options for restoration of flow in NSTEMI?
4 listed
- Primary angioplasty
- Thrombolysis
- Nitrates
- CABG
Which drugs are used in the future prevention of an MI following a recent MI?
(MI-5)
Aspirin ACEI (ramipril) B-Blocker (e.g. bisoprolol) Clopidogrel Statin
What is the MOA of ramipril?
ACE inhibitor - affecting the RAAS promoting Na and H20 retention.
What is the MOA of simvastatin?
Inhibits HMG CoA reductase (involved in cholesterol synthesis) therefore decrease in LDL
What is the MOA of clopidogrel?
Pro drug (converted by CYP enzymes) - irreversibly blocks P2Y12 components of adenosine receptors on platelet surface
Which 2 drugs are used as dual antiplatelet therapy post PCI?
Aspirin and clopidogrel
What is the MOA of bisoprolol
B blocker - decreases sympathetic drive + HR + myocardial contractility
It selectively blocks catecholamine stimulation of β1-adrenergic receptors in the heart and vascular smooth muscle.
What is Losartan + its MOA?
ARB - angiotensin II receptor blocker.
Blocks vasoconstriction properties of aldosterone release - for people with low tolerance to ACEI
What does the TIMI score predict?
35 day risk of further event post MI
What does the GRACE score predict?
All cause mortality in hospital at 6 months post MI
What’s the arrhythmic complication of an MI?
VF ( risk greatest in the 1st hour)
What are the mechanical complications of MI?
Scarring of muscle –> cardiac tamponade
Damage to papillary muscle = regurge + pulmonary oedema
In which layer of the arterial wall do atherosclerotic plaques develop?
Tunica intima
What is the step which initiates development of an artherosclerotic plaque?
Endothelial dysfunction
Which cells become foam cells?
Macrophages
What are the 2 methods of atheromatous thrombosis?
Erosion / rupture of plaque
What is the mechanism of erosion of an atheromatous plaque?
Inflammatory cells producing proteases which cut endothelial cells away from the vessel wall
What makes an atheromatous plaque unstable?
Thin cap - disordered collagen, large lipid core, high density of macrophages producing expressing TF and MMPs, large no of vaso vasorum
What are vaso vasorum?
Blood vessels within walls of large blood vessels
Where do long chain FAs enter the circulation?
left subclavian vein - from thoracic duct
Which hormone stimulates uptake of FA from the blood into fat and muscle tissue?
Insulin
What is the treatment for hyperlipidaemia?
Lifestyle advice ; statins ; fibrates
What is the MOA of fibrates?
Decrease serum TG by via PPAR-a
Decrease production and increase uptake
increase cholesterol excretion
What should be monitored in pts on fibrates for treatment of hyperlipidaemia?
Kidney function - fibrates can increase creatinine levels
What is tendinous xanthomata a diagnostic sign of?
Familial hypercholesterolaemia
