M.I. 01.15 Flashcards
Conversion of arachadonic acid in cell membranes to prostaglandin h2 (prostoglandin precursor) is by which enzyme?
COX - cyclo oxygenase
This enzyme converts prostaglandin H2 into Prostacyclin, PGE2 and PGD/PGF
Cox 1
This enzyme in platelets converts prostaglandin H2 into Thromboxane A2
Cox 2
Thromboxane A2 is bad for the CVS in 2 ways
- Platelet agonist - promotes clots
2. Vasoconstrictor
Arachidonic acid is converted to Leukotrienes (causing broncho constriction) by which enzyme
Lipo oxygenase
Which prostaglandin is protective for the stomach
PGE2
What 3 groups of prostaglandins
are converted from prostaglandin H2 (PGH2) by COX1, & have what 3 main effects?
- PDG / PGF - pro inflammatory, pain fever
- PGE2 - protective for stomach
- PGI2/ Prostacyclin - protective for vasculature -platelet inhibition & vasodilation
What 3 main effects do non-selective NSAIDs have on body e.g. Aspirin, Ibuprofen
- Reduce inflammation
- Reduce stomach protection - GI irrit.
- Reduce thromboxane prod - prevent platelet function
Celecoxib, Meloxicam, Etodolal are all examples of what type of NSAID
Cox 2 selective
This is a pro-drug, activated by CYP450, which blocks ADP receptor on platelets, thus preventing platelet activation
Clopidogrel
How do ACE inibitors control BP
Prevent conversion of angiotensin I to angiotensin II
Digoxin is an example of what type of inotrope
Positive - increases contractility of heart
Bisoprolol is an example of what type of inotrope
Negative - decreases contractility of heart
Familial hypercholesterolaemia (IIa) is associated with disorder of which chromasome?
19
These lipoproteins carry fat from the intestine - they release triglycerides & some cholesterol in the liver.
Chylomicrons
These lipoproteins transport cholesterol back to the liver for excretion and are associated with better health outcomes.
HDL
Unburned food metabolites are converted into this and secreted into the plasma by the liver
VLDL
3 main ingredients of chylomicrons?
Long chain f.a.s
Cholesterol
Protein
Frederickson type II lipid disorder assoc with what condition
Lipoprotein lipase deficiency
Frederickson type IIa lipid disorder assoc with what condition? (among others)
Familial hypercholesterolaemia
Frederickson type IIb lipid disorder assoc with what condition
Familial combined
hyperlipidemia
Frederickson type III lipid disorder assoc with what condition
Dysbetalipoproteine
mia
Frederickson type IV lipid disorder assoc with what condition (among others)
Familial
hypertriglyceridemia
Frederickson type V lipid disorder assoc with what condition
Diabetes
Diff between primary and secondary hyperlipidaemia?
1ary - inherited / genetic
2ary - assoc with other conditions e.g diabetes
These 3 conditions (and many more) are assoc with 2ary hyperlipidaemia
DM
Hypothyroidism
Nephrotic syndrome
Why should pregnant women be aware of their cholesterol
Risk of hyperlipidaemia
What 2 conditions may be assoc with these signs: •tendinous xanthomas •corneal arcus •premature CAD •family history of hypercholesterolemia
- Heterozygous familial hypercholesterolaemia
2. Familial defective apolipoprotein B
What condition is assoc with: •usually >30 yr old •often overweight •usually no xanthomas •premature CAD •different generations have different lipoprotein abnormalities
Familial combined hyperlipidemia
What condition is assoc with:
•premature CAD
•no xanthomas
•no family history of hypercholesterolemia
Polygenic hypercholesterolemia
yellow palmar creases assoc with what condition?
Dysbetalipoproteinemia
•often overweight •>30 yr old •often diabetic •hyperuriaemic •may or may not have premature CAD •determined by family history and HDL-C Assoc with what condit?
Familial hypertriglyceridemia
usually middle-aged •often obese •often hyperuricaemic •usually diabetic •risk for recurrent pancreatitis assoc with ?
Severe hypertriglyceridemia
What 3 criteria are definitive for familial hypercholesteraemia diagnosis?
- Total cholesterol above 7.5
mmol/l (in adults) - or LDL cholesterol above 4.9 mmol/l (in adults)
- PLUS tendon xanthomata in the patient or in a first- or second degr relative
Receptor for what substance is coded for on chromos. 19
LDL
Mutations in what receptor cause problems in FamHyperchol
LDL receptor
What drugs are HMG CoA reductase inhibitors - used for lowering cholesterol
Statins
ciprofibrate, gemfibrizil, bezafibrate, fenofibrate are examples of what triglyceride-lowering drugs
Fibrates
What are 2 types of atheromatous plaque
Concentric - fills whole lumen
Eccentric - sticks out into lumen
What initiates plaque formation in arteries (3 egs of causes)
Endothelial damage (smoking, hypertension, DM)
Once arterial damage occurs what is the next stage in atherosclerosis
Activation of platelets and monocytes - migrate to endothelial space. Smooth muscle cells proliferate here “remodelling”, cholesterol accumulates, WBCs absorb lipid & convert to fatty “foam cells”.
What forms the “fibrous cap” of a plaque
Collagen and smooth muscle cells
What would you see on ECG in a complete occlusion of coronary artery MI?
STEMI - st elevation
What would you see on ECG in a partial occlusion of coronary artery MI?
NSTEMI - st depression
