Ischaemic Heart Disease

Question 1

How does IHD manifest?

Answer 1

Angina or Myocardial Infarction

Question 2

What is the most common cause of IHD?

Answer 2

Impaired blood flow/thromboembolic occlusion

Due to atherosclerosis w/i coronary artery

Question 3

What are the non-modifiable risk factors for IHD?

Answer 3

Male gender

Family history

Question 4

What are the modifiable risk factors for IHD?

Answer 4

Smoking
Diabetes
Hypercholesterolaemia
Hypertension
Sedentary lifestyle
Obesity

Question 5

What are the two classifications of Angina Pectoris?

Answer 5

Stable

Unstable

Question 6

Describe stable angina

Answer 6

Atherosclerotic disease limiting the heart’s ability to respond to increased demand
Symptoms on exertion, relieved by rest

Question 7

Describe unstable angina

Answer 7

Generally due to plaque rupture, formation of non-occlusive thromboembolism or vasospasm (Prinzmetal)
Symptoms at rest

Question 8

What is angina diagnosis based on?

Answer 8

History
ECG
Angiography revealing stenosis

Question 9

What is the defining characteristic of ischaemic present on an ECG?

Answer 9

ST-segment depression

Question 10

How is angina managed non-pharmacologically?

Answer 10

Lifestyle advice (smoking, exercise, diet, weight reduction)
Coronary artery bypass grafting (CABG)
Angioplasty w/ stenting

Question 11

How does angioplasty w/ stenting work?

Answer 11

Balloon catheter dilates/destroys stenosis

Intraluminal stent prevents restenosis

Question 12

How is angina managed pharmacologically?

Answer 12

Nitrates - release of NO

NO causes venodilation AND coronary vasodilation

Question 13

What clases of drugs can be used for the prevention of IHD?

Answer 13

1 - Beta-Blockers
2 - Calcium Channel Blocker
Refractory disease - Beta-Blocker + DHP

Question 14

How are Beta-Blockers used for the prevention of IHD?

Answer 14

-ve inotropic and chronotropic effects reduce cardiac work
Slowing heart increases diastolic period (coronary flow)
Anti-arrhythmic effects AND reduced risk of MI

Question 15

How are Calcium Channel Blockers used for the prevention of IHD?

Answer 15

Vasodilation
Improved coronary blood flow
Verapamil/Diltiazem also myocardial depressant/bradycardic
Verapamil also anti-arrhythmic

Question 16

Do ACEIs have any value in IHD?

Answer 16

Ramipril shown to reduce mortality

Question 17

How are Potassium Channel Activators used for the prevention of IHD?

Answer 17

Target ATP-sensitive K+ channel - leads to hyperpolarisation

Question 18

What is Nicorandil?

Answer 18

A combined NO donor and kATP activator

Question 19

What antiplatelet drugs are available for treating IHD?

Answer 19

Low dose aspirin

Clopidogrel

Question 20

How does low dose aspirin work?

Answer 20

Inhibits endothelial AND platelet COX

Favours prostacyclin production (decreased thromboxane)

Question 21

What are the effects of Prostacyclin and Thromboxane?

Answer 21

Prostacyclin - Vasodilator

Thromboxane - Vasoconstrictor AND platelet aggregator

Question 22

Which type of cells can regenerate COX?

Answer 22

Endothelial cells (nucleated)
NOT platelets

Question 23

What drug may oppose the beneficial effects of low dose aspirin?

Answer 23

Ibuprofen

Question 24

How does clopidogrel work?

Answer 24

ADP receptor antagonist (preventing platelet aggregation)

Question 25

When is clopidogrel used?

Answer 25

In patients who cannot receive aspirin

Equally effective

Question 26

What is the ideal treatment regimen for angina?

Answer 26

Low dose aspirin AND/OR clopidogrel
BP controlled to <140/85
Hypercholesterolaemia to <5mmol (LDL<3)
GTN spray (symptomatic relief)

Question 27

What drug should be added when treating unstable angina?

Answer 27

Low molecular weight heparin