Cardiovascular Therapeutics - Angina and Myocardial Infarction

Question 1

What is atherosclerosis?

Answer 1

Deposition of fatty plaques in coronary arteries.

Question 2

What leads to the development of atherosclerosis?

Answer 2

Elevated low-density lipoprotein (LDL) cholesterol contributes development of atherosclerosis

Question 3

What is Angina characterised by?

Answer 3

Pain (or constricting discomfort) in the chest, neck, shoulders, jaw or arms

Question 4

What causes Angina?

Answer 4

Insufficient blood supply to the myocardium

Question 5

Types of Angina

Answer 5

Stable angina
Unstable angina

Question 6

Describe the types of angina

Answer 6

Stable angina - Predictable pain normally on exertion.
Almost always caused by atherosclerosis (plaque)

Unstable angina - Pain with less and less exertion or at rest.
Normally caused by a ruptured atherosclerotic plaque.

Question 7

Management of Angina

Answer 7

Sublingual glyceryl trinitrate for relief of angina symptoms.

Beta blocker or calcium-channel blocker also for symptom relief.

Secondary prevention: Antihypertensive Depending on bleeding risk and comorbidities - antiplatelet treatment

Question 8

How are angina symptoms relieved with organic nitrates?

Answer 8

Trigger vasodilation:
Dilate coronary arteries, improving perfusion (but only slightly)
Dilate veins, reducing venous return to heart and reducing workload.
Reduce oxygen demand and relieve angina symptoms

Question 9

Does sympathetic nervous system regulate cardiac output?

Answer 9

Yes

Question 10

Mechanism of beta blockers used to treat the symptoms of angina

Answer 10

Reduce workload and oxygen demand of the heart by inhibiting sympathetic stimulation of heart (via β1 adrenergic receptors)

Question 11

Mechanism of calcium channel blockers used to treat the symptoms of angina

Answer 11

Reduce workload and oxygen demand of the heart by reducing Ca2+ entry into cardiac myocytes via L-Type Calcium channels.

Question 12

What causes myocardial infarction (MI)?

Answer 12

Caused by blockage of the coronary artery following rupture of atherosclerotic plaque and thrombus formation.

Question 13

Types of MI

Answer 13

MI further classified based on the Electrocardiogram (ECG) recording:
if ST segment is elevated then termed STEMI
if ST segment normal then classed as NSTEMI

Question 14

Early management of MI

Answer 14

Aspirin (in the ambulance!)
Reperfusion therapy - Angioplasty (stenting) or fibrinolysis (to dissolve clot)
Antiplatelet drugs
P2Y12 antagonist (prasugrel, clopidogrel)

Question 15

Why are platelets important in MI?

Answer 15

They are central to thrombus (clot) formation following plaque rupture in a coronary artery.