Anti-Anginal Agents Flashcards
angina pectoris
Angina is the primary symptom of ischemic heart disease
temporary and reversible imbalance between myocardial O2 supply and demand
increased demand - from HR, ventricular contraction, and ventricular wall tension
decreased supply – from coronary blood flow, O2 carrying capacity of blood, or both
coronary artery disease (CAD) usually the underlying cause
sensation of angina?
Heavy pressing substernal discomfort (rarely called pain)
Often radiating to left shoulder, flexor aspect of left arm, jaw, or epigastrium
typical angina
= exertional angina
Usually fixed atherosclerotic narrowing of an epicardial coronary artery on which exertion or emotional stress superimposes an increase in myocardial O2 demand
Hx = angina induced by exercise, relieved by rest and/or nitroglycerin (NTG)
lasts no longer than 15 min,
5 - 15 episodes/wk
ST segment depression
atypical angina
= angina at rest
(other names: variant, vasospastic, prinzmetal’s)
- Focal or diffuse coronary vasospasm episodically reduces coronary flow
- Transient ST segment elevation during angina
unstable angina
Rupture of an atherosclerotic plaque, with consequent platelet adhesion and aggregation decreased coronary blood flow
Abrupt decreases in blood flow due to thrombus or embolus signals impending myocardial infarction (MI)
If symptoms not relieved by 3 NTG tablets within 15 minutes should call 911 or get to nearest ED immediately
agents used to tx angina?
- Beta blockers: decrease HR/contractility
- Ca channel blockers: some decrease HR/contractility, others affect preload/afterload
- vasodilators: increase coronary blood flow
- statins/anti-thrombotics: increase regional myocardial blood flow
how to tx exertional angina?
decrease work on heart: decrease HR and contractility
- Beta blockers + aspirin
- Beta blockers + aspirin + long acting nitrates
- nitrate for acute attacks
- ACEI’s for DM or left ventricular dysfunction
how to tx unstable angina?
increase blood flow and decrease work of heart
Acute: MONA: morphine, O2, nitroglycerine, aspirin
+ Beta blocker
If b blocker contraindicated –verapamil or diltiazem if no LV dysfunction
increase blood flow – antiplatelet agent (aspirin) + heparin to decrease thrombus
Percutaneous coronary interventions (PCI) - Angioplasty, placement of stents
Coronary bypass grafts (CBG) (“cabbage”)
Thrombolytics (Alteplase, Reteplase, Tenecteplase, Streptokinase)
how to treat prinzmental’s angina?
relax the vasculature
mechanism of organic nitrates
they are the source of nitric oxide
- NO decreases both preload and afterload by relaxing vascular smooth muscle
- relaxation of large vv –> decrease venous return–> decreased preload –> decreased O2 demand
- directly dilate coronary arteries
nitrates and exertional angina?
can’t directly infuse NTG into heart, does not relieve exertional angina
- must take sublingual NTG (because it must be converted to nitric oxide first)
how is NTG activated?
nitrates + endothelial cells result in NO
NO converts guanylyl cyclase –> which converts GTP to cGMP
cGMP increases mosin LC –> relaxation
*** NOTE: phosphodiesterase inactivates cGMP
Nitroglycerin (NTG)
= nitrate vasodilator
Sublingual tablet or spray (PRN), sustained-release oral capsules BID/QID, buccal tablets or gel Q3-5hr, ointment Q4-8 hr, dermal patch 12-16 hr/day
isosorbide dinitrate
long acting nitrate vasodiator
SE’s of nitrates?
headaches, facial flush, dizziness, orthostatic hypotension (worsened by alcohol)