Term
| What is the pathophysiology of angina? |
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Definition
Coronary arteries have atherosclerotic plaques and can't dilate during exertion
Coronary arteries can't inc. flow
Imbalance of cardiac O2 demand and supply
Ischemia
Angina |
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Term
| Factors that affect cardiac O2 demand (3) |
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Definition
HR
dp/dt
LV wall tension
Diastolic tension determined by: preload, radius
Systolic tension determined by: preload, dp/dt, afterload |
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Term
| Subepicardium is perfused during ___ while the endocardium is perfused during ___ |
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Definition
Systole and diastole
Diastole (systole squeezes the arteries shut) |
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Term
| What is the rate-pressure product? |
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Definition
| Rate-pressure product = HR x SBP |
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Term
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Definition
| Wall tension = intraventricular pressure x radius/(2 wall thickness) |
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Term
| What does the rate-pressure product tell us? |
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Definition
Incorporates the major factors that determine O2 demand = measures myocardial O2 demand
In pt w/ stable angina, when rate-pressure product reaches some constant value pt will develop angina
Decreasing rate-of-rise of the rate-pressure product inc. exercise tolerance |
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Term
| Angina can be prevented/relieved by...(2) |
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Definition
Dec. cardiac O2 demand
Inc. cardiac O2 delivery |
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Term
| Cardiac O2 demand can be dec. by...(3) |
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Definition
Prevent exercise symp.-mediated inc. of HR and dp/dt
Dec. preload = dec. wall tension during the systole and diastole
Dec. afterload = dec. wall tension during systole |
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Term
| Cardiac O2 delivery can be inc. by...(4) |
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Definition
Dilate large epicardial arteries and endocardial arterioles
Inc. collateral flow to ischemic areas
Dec. preload = dec. wall tension during systole and diastole
Dec. HR |
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Term
| Classes of anti-anginal drugs |
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Definition
B-blockers
Nitrate VD
Ca channel blockers |
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Term
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Definition
Atenolol
Metoprolol
Propranolol
Timolol |
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Term
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Definition
Block B-adrenoR
Prevent symp. nervous system from stim. the heart |
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Term
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Definition
Dec. HR = inc. time in diastole = inc. blood flow to endocardium
Dec. dp/dt = dec. wall tension during systole
Dec. afterload |
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Term
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Definition
Bronchoconstriction
Dec. dp/dt = acute exacerbation of HF
Sudden withdrawal can cause MI |
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Term
| Isosorbide nitrates and topical NTG, late sublingual NTG: MOA, effects |
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Definition
Dilate veins
Dec. preload = dec. wall tension during systole and diastole = dec. O2 demand, inc. endocardial blood flow
(afterload unchanged) |
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Term
| Isosorbide nitrates and topical NTG, late sublingual NTG have no effect on... |
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Definition
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Term
| Nitrates: summary of effects |
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Definition
| Dec. preload = dec. systolic and diastolic wall tension = dec. O2 demand, inc. subendocardial blood flow |
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Term
| What effect do nitrates have on platelet aggregation? |
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Definition
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Term
| How can one avoid tolerance to nitrates? |
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Definition
Disappears after the drug is w/drawn for a short period of time = use an appropriate dosing schedule
Remove patches at night, dose p.o. at 7am and 2pm |
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Term
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Definition
Headache (lets you know the pills are still active)
Orthostatic hypotension |
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Term
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Definition
CHF (dec. venous return)
MI (minimize size of tissue damage) |
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Term
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Definition
Amlodipine
Diltiazem
Felodipine
Verapamil |
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Term
| Verapamil, diltiazem: MOA/effects |
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Definition
Dec. AV conduction, HR, dp/dt (dec. wall tension during systole), SV, CO
A little relaxation of arteriolar smooth muscle = small dec. in DBP (but not enough to cause a baroreflex inc. in sympathetic activity) |
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Term
| Verapamil, diltiazem: summary of effects |
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Definition
Dec. HR
Dec. dp/dt, DBP = dec. wall tension during systole
Dilate epicardial and endocardial arterioles!!!
Inc. endocardial and collateral blood flow |
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Term
| CCAs are effective in ___ angina b/c ___ |
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Definition
Prinzmetal's
Prevent the vasospasm in the epicardial arteries |
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Term
| Verapamil, diltiazem: S/E |
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Definition
Bradycardia (counteract w/ CaCl)
SA nodal failure, AV block
HF in patients w/ systolic dysfxn
Inc. risk of MI from excessive VD causing inc. sympathetic drive (come in slow release)
Hypotension
GERD
Verapamil: constipation |
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Term
| Verapamil, diltiazem: drug-drug interactions |
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Definition
Verapamil IV: +B-blockers = overt HF or severe bradycardia w/ AV block
Verapamil: can inc. plasma [digoxin]
Verapamil, diltiazem: +digoxin potentiate slowing of AV conduction
Diltiazem: +cimetidine blocks CYP and can inc. plasma [diltiazem] |
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