Anti Anginal Drugs Flashcards
When does most of coronary blood flow occur?
85% during diastole
What are the major regulators of coronary blood flow?
Local metabolites that cause vasodilation (such as adenosine)
In what situations would myocardial O2 demand be increased?
Exercise
Sympathetic stimulation
Tachyarrhythmias
In what situations would you have decreased coronary artery blood supply?
Systemic hypotension
Vasospasm
Thrombus/Embolus
What class of drugs is comprised of potent vasodilators used in angina?
Nitrates
first line therapy for stable angina
Nitrates
MOA
NO Donors functioning independently of endothelial cells.
Activation of guanylyl cyclase, more cGMP made, less MLCK activation, more smooth muscle relaxation
What are the physiological effects of nitrates?
Venodilation Decreased venous return Reduced LV Wall Tension Reduced afterload Direct coronary artery vasodilation
Clinical Uses of Nitrates
Angina Pectoris (Stable, Unstable, Prinzmetal)
HTN Emergencies
CHF
Prevent or reduce exercise-induced myocardial ischemia
Nitrates
Adverse Effects
Orthostatic hypotension
reflex tachycardia (baroreceptor)
Headache
Tolerance
Describe the role of Ca2+ in vascular smooth muscle EC coupling
Ca2+ enters cell, binds calmodulin, which will activate MLCK (through phosphorylation). That will eventually phosphorylate myosin light chain to cause muscle contraction
Ca2+ Channel Blockers are potent anti-arrhythmics. Why?
SA/AV node fibers use Ca2+ for their phase 0 depolarization and phase 4 depolarization
Ca2+ Channel Blockers
Clinical Uses
Angina Pectoris HTN Arrhythmias Hypertrophic Cardiomyopathy Migraines Raynaud's phenom (vasospasm of peripheral vessels upon cold exposure)
Which Ca2+ Channel Blocker has the greatest vasodilatory effects?
Nifedipine
Has the most vascular smooth muscle selectivity
Which Ca2+ Channel Blocker has the best negative chronotropic and inotropic effects?
Verapamil
Diltiazem is a close second
Verapamil
Adverse Effects
Bradycardia CHF Heart Block Hypotension Constipation
