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31 Cards in this Set
- Front
- Back
what is angina pectoris |
• chest pain due to myocardial ischaemia |
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the pain which is associated with angina pectoris is due to what happening |
a build up of metabolites in the interstitial space: -adenosine (from broken down ATP) -CO2 -lactate -K+ ions these metabolites then activate sensory nerves |
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what causes myocardial ischemia |
increased myocardial O2 demand which is not met |
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what are the 3 types of angina |
stable angina unstable angina variant angina |
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what is the most common and what is the least common form of angina |
stable agnina --> most common variant angina --> least common |
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are attacks predictable or non predictable in stable, unstable and variant angina |
stable --> predictable unstable --> non-predictable variant --> unpredictable
....makes sense doesn't it |
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what causes stable angina |
myocardial O2 demand not being met |
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what triggers stable angina |
exercise or stress |
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is atherosclerosis present in stable angina |
yeaaaaaaaaaaaah |
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how would you treat angina |
cholesterol lowering drugs (statins) |
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what causes unstable angina |
coronary artery occlusion due to platelet adhesion to ruptured atherosclerotic plaque |
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how would you treat unstable angina |
anti-platelet drugs |
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what causes variant angina |
coronary artery occlusion by vasospasm vasospasm causes intense vasoconstriction of coronary artery |
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in what forms of angina is dilation helpful |
variant angina because it can relax the vasospasm |
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why is dilation of the coronary arteries dangerous in stable and unstable angina |
because it may cause coronary steal this is where dilatation can occur, this sends more blood to already well perfused areas, but where dilatation cannot occur, less blood is delivered because of the fall in input pressure |
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a decrease in what is helpful in all forms of angina |
a decreased myocardial Oxygen demand |
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what 2 forms of drugs exist to reduce myocardial oxygen demand |
1) drugs acting directly on the heart: 2) drugs that cause vasodilation |
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what are the drugs which act directly on the heart to redcue myocardial oxygen demand |
b1-adrenoceptor blockers – competitive reversible antagonists of adrenaline and noradrenaline at cardiac b1- adrenoceptor decrease heart rate and force decrease myocardial work decrease myocardial O2 demand |
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give 2 examples of adrenoceptors |
propano......lol (Beta 1&2) atenolol (Beta 1 selective) |
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what are the adverse affects of beta-adrenoceptor blockers in agnina |
(a) Exacerbate asthma (block of b2- adrenoceptors in bronchi - avoid by use of alternative drug class) (b) Intolerance to exercise (c) Hypoglycaemia (d) Blockade of b-adrenoceptors may uncover a1- mediated constriction in coronaries |
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adenosine and lactate are powerful vasoconstrictors, how do they aid/not aid the situations in different forms of angina |
in stable and unstable angina they are bad because they act as coronary vasodilators in variant they can self resolve the angina due to their vasodilator function |
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which drug was recently introduced to treat all forms of angina |
ivabradine |
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how does ivabradine work |
Blocks If (Na+) current that contributes to SA node depolarisation towards threshold Decreases heart rate but not force decreases myocardial O2 demand |
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what 3 things to drugs which cause vasodilation to achieve lowered myocardial oxygen demand do which |
-dilation of arteries -dilation of veins -venous dilation |
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in vasodilator drugs what happens during the dilation of the arteries |
decreased after-load (force against which left ventricle contracts) decreased myocardial work |
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in vasodilator drugs what happens during the dilation of the veins |
decreased pre-load (the diastolic pressure that distends the relaxed left ventricle) |
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in vasodilator drugs what happens during the venous dilation |
decreased venous return decreased pre-load decreased strength of contraction decreased myocardial work |
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what type of drugs are the most commonly used anti anginals |
nitrovasodilators |
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give 2 different examples of nitrovasodilators |
• glyceryl trinitrate (nitroglycerine, 10% in inert lactose base) • taken as sub-lingual tablet or spray • amyl nitrite (volatile liquid) • vials opened and inhaled • not now used clinically but has become drug of abuse (poppers) Both drugs rapid in onset, but action short-lived Uses: • prophylaxis in stable angina (i.e. taken immediately before exercise) • rapid relief of ongoing anginal attack (all forms) |
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give 2 other nitrovasodilators |
isosorbide dinitrate isosorbide mononitrate • taken orally |
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how do nitrovasodilators work |
• nitrovasodilators all lipophilic - readily enter smooth muscle cells and are reduced to nitric oxide (NO) • nitrovasodilators termed “NO donors” |