Angina Flashcards
Stable vs stable angina
Stable = predictable. worse with exercise
Unstable = occurs without activity
Variant angina
Coronary artery vasospasm
Microvascular angina
Spasms in smallest coronary arteries
Pain is longer lasting
More common in women
Antianginal drug goals
Improve blood flow in coronary circulation
reduce heart muscle metabolic demands
Organic Nitrates
cause relaxation of smooth muscle
dilate coronary arteries
reduce preload and afterload
Organic Nitrates available forms
Sublingual
Oral capsules/tablets
IV
Ointments
Patches
Sprays
Organic Nitrates mechanism
Vasodilation
Dilates coronary arteries which causes increased coronary blood flow
Useful in variant angina
Reduces cardiac preload (relaxes veins)
Reduces cardiac afterload *relaxes systemic arteries)
Decreased preload vs decreased afterload
Preload is stress on the ventricular wall before systole. Volume of blood in ventricles end of diastole/before systole.
Decreased preload = dilate veins. Decreases stroke volume and cardiac output and BP = decreased cardiac work
Afterload is resistance the heart has to pump against.
Decreased afterload = arteriolar vasodilator and so decreased BP = decreased cardiac work
Nitroglycerin
Organic nitrate
Large first-pass effect
Sublingual
IV form for BP control in perioperative hypertension, HF tx, ischemic pain, pulm edema
Isosorbide Mononitrate
Organic nitrite
oral (high bioavailability)
Prolonged action for prophylaxis
Nitrate form for acute, prophylaxis in provoking situations, and long-term prophylaxis
Acute: SL tablet or spray
Prophylaxis in situations that may provoke: SL, oral
Long-term prophylaxis: patch, oral
Organic Nitrate ADVERSE EFFECTS
Headache
-Classic and predictable in almost all patients
Postural hypotension
Reflex tachycardia
Partially offsets beneficial effects. can combine w beta blocker
can build tolerance
How to reduce nitrate tolerance
Removal of old medication
remove topical forms at bedtime
Beta blockers
-B-adrenoreceptor antagonists
-Decrease HR
-Decrease contractility
-long-term prevention of angina. NOT for acute exacerbations
Atenolol
Metoprolol
propranolol
Calcium Channel Blockers
First-line tx of angina
Reduce contractility (negative inotropic) - verapamil and diltiazem
Peripheral arterial vasodilation - all calcium channel blockers
Decreased myocardial oxygen demand
•Diltiazem
•Varapamil
•Nifedipine (DHPs. end in “pine”)