Angina

Question 1

basis of ischemia

Answer 1

myocardium not getting the oxygen it demands. is an issue with oxygen delivery. coronary blood flow is the supply to the heart

Question 2

angina

Answer 2

clinical syndrome characterized by discomfort in the chest, jaw, shoulder, back, and or arm. typically aggravated by exertion or emotional stress. relieved by nitroglycerin

Question 3

metabolic effects of ischemia

Answer 3

anaerobic glycolysis is inadequate to maintain cell functions. ATP and creatine phosphate levels fall. Intracellular and extracellular acidosis develops. Extracellular levels of potassium, lactate, phosphate, and fatty acid levels rise.

Question 4

most important contributor to elecrtophysiologic changes of ischemia

Answer 4

elevated extracellular potassium. causes the changes we see on ECG

Question 5

injury currents (systolic current_

Answer 5

in subendocardial injury, the action potential of ischemic cells is more negative than that of normal cells in phase 2 and 3. during electrical systole, intracellular positive current flows from normal cells to ischemic cells

Question 6

what is best way to diagnose ischemia?

Answer 6

stress test + imaging!

Question 7

4 main risk factors for cardiovascular disease

Answer 7

lipid abnormalities, smoking, diabetes, hypertension

Question 8

aspirin

Answer 8

irreversible inhibition of platelet cyclooxygenase (COX). COX is required for prostaglandin and thromboxane synth. adverse effect is bleeding. reduces mortality!

Question 9

ticlopidine

Answer 9

not often used. inhibits platelet aggregation. reduces blood viscosity. not shown a decrease in adverse events in patients with stable angina. induces neutropenia and rarely TTP

Question 10

clopidogrel

Answer 10

greater antithrombotic effect than ticlopidine. selectively and irreversibly inhibits the binding of adenosine diphosph to its platelet receptors. used in acute management.

Question 11

prasugrel

Answer 11

thienopyridine class. irreversibly binds to the P2Y12 receptor. used to reduce thrombotic cardiovascular events during an acute coronary syndrome for those who have received a percutaneous coronary intervention (stent). good antiplatelet, but high risk of bleeding. must be less than 75 and lighter than 60kg in weight, with no stroke history

Question 12

ticagrelor

Answer 12

similar in structure to adenosine. blocks ADP receptors. does not require hepatic activation. faster onset. also eliminated faster

Question 13

dipyridamole

Answer 13

increases intracellular platelet cyclic adenosine monophosphate. use is limited because it vasodilates coronary arteries which can enhance exercise induced ischemia

Question 14

cilostazol

Answer 14

inhibits cellular phosphodiesterase. causes increase in cAMP levels which results in inhibition of platelet aggregation. causes vasodilation, can cause increased mortality in heart failure patients

Question 15

lipid lowering agents

Answer 15

decrease the risk of adverse ischemic events in patients with established CAD. side effects are muscle aches

Question 16

ACE inhibitors

Answer 16

prevents angiotensin I -> angiotensin II. Angio II causes vasoconstriction. ACE also degrades bradykinin, a vasodilator. ACE inhibitors increase bradykinin levels. all end in -pril. dry cough, hypotension, hyperkalemia, angioedema side effects

Question 17

beta blockers

Answer 17

prevent MI and sudden cardiac death. reduce angina and ischemia. bind to beta receptors and blunt effect of sympathetic system. decreases myocardial oxygen demand. increase survival post MI. end in -lol. side effects are fatigue, lethargy, insomnia, claudication, impotence

Question 18

when to not use beta blockers

Answer 18

bradycardia, high degree AV block, sick sinus syndrome, unstable LV failure. Asthma, bronchospastic disease, severe depression, peripheral vascular disease

Question 19

nitrates

Answer 19

endothelium independent vasodilators. activate smooth muscle guanylyl cyclase to form cGMP, which prevents calcium entry and muscle contraction. vasodilation reduces ventricular preload, reducing ventricular wall stress. inhibits platelet aggregation. inhibits leukocyte endothelial interactions (anti-inflamm). can develop nitrate tolerance with chronic use. headaches, hypotension, bradycardia due to Bezold Jarisch reflex

Question 20

nitrates contraindications

Answer 20

hypertrophic cardiomyopathy, severe aortic stenosis, significant hypotension, use of phosphodiesterase inhibitors for ED

Question 21

calcium channel blockers

Answer 21

reduce transmembrane flux of calcium via calcium channels. vasoselective dihydropyridines and non-dihydropyridines. vasoselective: dilatecoronary arteries and resistance vessels. negative inotropes. decrease conduction velocity and prolong repolarization in SA node and AV node, decreasing heart rate. hypotension, heart failure, peripheral edema, constipation side effects