Cardiology

Question 1

What is the MOA of aspirin?

Answer 1

Antiplatelet - inhibits COX-1 (cyclo-oxygenase), which prevents production of thromboxane A2 and inhibits platelet aggregation.
(Also has NSAID properties and can be used to reduce pain and inflammation).

Question 2

What is aspirin prescribed for?

Answer 2

Secondary prevention following MI, TIA and stroke and for patients with angina or peripheral vascular disease.

Question 3

What is the MOA of clopidogrel, prasugrel and ticagrelor?

Answer 3

Antiplatelet drug - ADP receptor antagonists that inhibit the binding of ADP to the P2Y12 receptor on platelets, which inhibits the activation of the GPIIb/IIIa complex and inhibits platelet aggregation.

Question 4

What is the MOA of warfarin?

Answer 4

Inhibits the Vitamin K-dependent synthesis of clotting factors II, VII, IX and X, as well as protein C, protein S and protein Z

Question 5

What is warfarin mainly prescribed for?

Answer 5

Treatment of AF and in people who have had blood clots.

Question 6

What is the MOA of apixaban?

Answer 6

DOAC - inhibits Xa, leading to reduced clotting

Question 7

Why are DOACs increasingly used over warfarin?

Answer 7

Don’t require monitoring in the way that warfarin does (weekly INR checks).

Question 8

What is the MOA of beta blockers?

Answer 8

Block B-adrenoceptors, blocking B1 causes decrease in inotropy and chronotropy, blocking B2 causes peripheral vasoconstriction and bronchoconstriction

Question 9

What is the MOA of bisoprolol vs propranolol?

Answer 9

Bisoprolol - B1 selective beta blocker

Propranolol - non-selective beta blocker

Question 10

What are the uses of beta-blockers?

Answer 10

Angina, hypertension, post MI, heart failure

Question 11

Name some contraindications for beta blockers

Answer 11

Severe asthma/COPD

Heart block

Question 12

Name some side effects of beta blockers

Answer 12

Lethargy
Erectile dysfunction
Headaches
Nightmares

Question 13

What are the uses of ACEi?

Answer 13

Hypertension
Heart failure
Post-MI

Question 14

What is the MOA of ACEi such as ramipril?

Answer 14

Inhibit ACE enzyme, which inhibits conversion of angiotensin I to angiotensin II. Absence of potent vasoconstrictor angiotensin II and aldosterone leads to peripheral vasodilation and a decrease in BP

Question 15

What is the most common side effect of ACEi and why does this occur?

Answer 15

Dry cough

ACEi bind to substrate instead of bradykinin, leads to excess bradykinin.

Question 16

What type of diuretic is furosemide and how does it work?

Answer 16

Loop diuretic
Inhibits co-transporter Na/2Cl/K in loop of henle, leads to reduced ion reabsorption and therefore reduced water reabsorption, causing a diuretic

Question 17

What is the MOA of adenosine?

Answer 17

Blocks AVN conduction, it is commonly used to treat certain forms of supraventricular tachycardia.

Question 18

What is the MOA of ivabradine?

Answer 18

Inhibits the funny current in cardiac pacemaker cells leading to a slower pulse,it is used to treat heart failure.

Question 19

What is the MOA of digoxin?

Answer 19

Increases the force of contraction of cardiac muscle by blocking the Na+/K+ pump, is used to treat heart failure or AF as it helps make the heart beat stronger and more regular.

Question 20

What is the MOA of the anticoagulant dabigatran?

Answer 20

Direct thrombin inhibitor

Question 21

What is the MOA of the anticoagulant fondaparinux?

Answer 21

Xa inhibitor, reduces clotting.

Question 22

What is the meaning of inotropy and chronotropy?

Answer 22

Inotropy - force of contractility

Chronotropy - rate of contraction

Question 23

What is the main use of furosemide?

Answer 23

Heart failure

Question 24

What is the MOA of thiazide-like diuretics such as bendroflumethiazide and indapamide?

Answer 24

Inhibits NaCl transporter in DCT, leads to a natiuresis and diuresis.

Question 25

What is the MOA of K+ sparing diuretics e.g. Spironolactone, amiloride? What is the difference between the actions of these 2 examples?

Answer 25

Spironolactone is an aldosterone antagonist that directly blocks aldosterone receptors. Amiloride inhibits ENaC. Both lead to a natiuresis and diuresis.

Question 26

What is the MOA of GTN spray?

Answer 26

It's a nitrate that cause vasodilation of veins and large arteries, reducing pulmonary vascular resistance and decreasing the preload.

Question 27

What is the MOA of calcium channel blockers?

Answer 27

Decrease cell entry of Ca2+ via L-type voltage-gated Ca2+ channels in smooth muscle, promoting coronary and peripheral artery vasodilation. There are 3 classes: dihydropyridines, phenylalkylamines and benzothiazepines.

Question 28

What is the difference in dihydropyridine and non-dihydropyridine calcium channel blockers? Give examples of drugs.

Answer 28

Dihydropyridines e.g. Amlodipine - mainly peripheral and coronary vasodilators that cause a reflex tachycardia so are often given with beta blockers. Non-dihydropyridines e.g. Verapamil, diltiazem - have vasodilation effects as well as slowing conduction at the SAN and AVN, never give with beta blockers.

Question 29

What is digoxin toxicity?

Answer 29

Digoxin toxicity/poisoning occurs when someone takes too much digoxin. It can lead to electrolyte imbalances and arrhythmias.

Question 30

What is the MOA of class I antiarrhythmic drugs (Vaughn Williams classification) e.g. Lidocaine, flecanide?

Answer 30

Block sodium channels, reducing fast depolarisation of cardiac myocytes.

Question 31

What is the MOA of class III antiarrhythmics e.g. Amiodarone?

Answer 31

Prolongs the action potential, reducing the possibility of tachyarrhythmias.