anti-anginal drugs Flashcards
Name 3 pathophysiologies of angina pectoris
- progressive occlusion by atherosclerotic plaque
- unstable plaque (evolving clot)
- vasospam
where does the actual pain come from with angina pectoris
- secondary to metabolite spill from HYPOXIC cells (especially adenosine leakage), which stimulates pain fibers
angina occurs when oxygen _____ exceeds oxygen ____
demand; supply
what is the main pharmacological goal of relieving angina
- decreasing myocardial oxygen demand, or increasing oxygen supply (less commonly)
What is the role of autoregulation of coronary blood flow?-
- limits ability to increase O2 supply
Name the two determinants of oxygen supply
- patency of blood vessels
2. length of diastole
Name the three determinants of oxygen demand
- heart rate
- contractile force
- ventricular wall stress
What two components are a part of ventricular wall stress? define them
- preload: amount of stretch of ventricular wall prior to systole… determined by LV end diastolic pressure and volume
- with more stretch you get more of a contractile force –> more meatbolism that requires more oxygen consumption and demand
- afterload: force districuted in ventricular wall during systole; determined by the peripheral vascular resistance
- with more afterload, you need to do more work, so you have increased oxygen consumptoin and demand
what receptor in the body, when stimulated, increases contractility how about heart rate?
- Beta 1 adrenergic for both
What is the relationship between heart rate and the length of systole? diastole?
- no relationship between heart rate and systole; heart rate is inversely related to length of diastole
what treatment do you use to decrease ventricular wall stress?
- Organic nitrates, calcium channel blockers, ranolazine
what treatment do you use to decrease cardiac contractility
beta blockers, some calcium channel blockers, ranolazine
what treatment do you use to increse O2 supply in heart
- anti-platelet agents (aspirin, clopidogrel, integrin blockers)
- Thrombolytics (streptokinase, tPA)
what do you use to reduce oxygen demand of heart via decreasing HR
- beta blockers
what is the another name for organic nitrates
- nitrovasodilators
Name three common organic nitrates and their MOA
- glyceryl trinitrate (NTG)
- Isosorbide mononitrate
- isosorbide dinitrate
NO donors to give vasodilation
What is the net effect of nitrovasodilators
- reduction of intracellular calcium and other effects – causes smooth muscle releaxation
What enzyme must be present to activate nitrovasodilators? what happens for activation
- ALDH-2; activation occurs when NO is released from the compound
how does tolerance work with nitrovasodilators
- suicide inhibition of ALDH-2; inhibits itself with bioactivation
Give pathway of NTG
- ALDH-2 activation of the nitrovasodilators to release NO
- NO acts on smooth muscle guanylyl cyclase to form cGMP
- cGMP activates cGMP dependent protein kinase which will decrease intracellular calcium levels