P14: Ischaemic Heart Disease Angina

Question 1

Does coronary perfusion happen in systole or diastole

Answer 1

only diastole

Question 2

What local metabolic methods control coronary artery diameter

Answer 2

Local, transient ischaemia causes the release of vasoactive metabolites

Question 3

What autonomic methods control coronary artery diameter

Answer 3

Larger coronary vessels = alpha1-adrenceptors, constriction

Smaller arteries = beta2-adrenceptors, relaxation

Question 4

What is coronary stenosis

Answer 4

The narrowing of the arteries, leading to insufficient oxygen supply to the cardiac muscle

Question 5

How is coronary stenosis often diagnosed

Answer 5

Sound of turbulent blood flow through the narrowed part of the artery

Question 6

What is angina pectoris

Answer 6

A sensation of chest squeezing and pain, particularly following excercise, linked to stenosis

Question 7

Is there a link between pain severity and myocardial oxygen deprivation

Answer 7

No, low pain can mean high deprivation and low deprivation

Question 8

What is stable angina (effort angina)

Answer 8

Classic form of condition
Pain is minimal at rest and develops upon exercise or stress
Symptoms classically fade rapidly on rest

Question 9

What is unstable angina (crescendo angina)

Answer 9

Angina that escalates
Commonly occur at rest or on minimal action
Severe and acute onset
Crescendo pattern - each episode is more severe than the last

Question 10

What is the difference in the pathological process between stable and unstable angina

Answer 10

Chronic atherosclerosis - stable

Acute vascular blockade - unstable

Question 11

What are the 3 stages of plaque development in athersclerosis

Answer 11

1. Abnormal accumulation of lipid
2. Fibrous tissue in the vessel wall narrows or occludes the vessel lumen
3. Reduced blood flow

Question 12

What is prinzmetal angina

Answer 12

coronary artery muscular spasm

Question 13

Rupture of vessel plaque can lead to what

Answer 13

rapid thrombus development

Question 14

What can untreated stable angina lead to

Answer 14

Unstable angina and then a heart attack

Question 15

Name some risk factors for angina

Answer 15

Hypertension
Hyperlipidaemia
Smoking
Diabetes Mellitus
Obesity
Being Male
Stress
Menopause
Systemic infections

Question 16

What is the goal of angina treatment

Answer 16

Reduce the workload of the heart and its oxygen consumption

Question 17

What is the equation for heart workload

Answer 17

Stroke volume x arterial pressure x heart rate

Question 18

What can affect heart workload besides the equation tings

Answer 18

Preload - venous return
Afterload - peripheral resistance
Sympathetic stimulation

Question 19

What are the 3 main classes of pharmacological treatment for angina

Answer 19

• Organic Nitrate Donors
• Beta-Adrenoceptor antagonists
• Calcium channel blockers

Question 20

Name some organic nitrate donor drugs for angina

Answer 20

Glyceryl trinitrate (short acting)
Isosorbide Dinitrate (long acting)

Question 21

Name some Beta-Adrenoceptor antagonists for angina

Answer 21

Propranolol

Atenolol

Question 22

Name some calcium channel blocker drugs for angina

Answer 22

Nifedipine

Nicardipine

Question 23

What are angina drugs supplemented with

Answer 23

Anti-platelets/Anti-thrombotics - aspirin

Antilipidaemic agents - statins

Question 24

Describe the mechanism of organic nitrates

Answer 24

Widespread peripheral vasodilation
- Reduces preload by action on venules
- Reduces after load by peripheral arteriolar relaxation
Some action on coronary artery dilation

Question 25

Give examples of organic nitrates

Answer 25

Glyceryl trinitrate | Isosorbide mono/dinitrate

Question 26

What are the half lifes of glyceryl trinitrate and isosorbide mono/dinitrate

Answer 26

``` GT = 2 minutes IS/D = 1 hour ```

Question 27

How are organic nitrates administered - give pros of each

Answer 27

Sublingual - fast acting, acute attack Oral/Transdermal "nitropatch" slow release: maintenance therapy IV - to control unstable angina

Question 28

What are the adverse affects of organic nitrates

Answer 28

- Vasodilation and hypotension - Met-haemoglobinaemia (increased O2 carrying capacity) - Tolerance due to depletion of tissue thiols

Question 29

Name some Beta-adrenoceptor antagonists and how they aim to work

Answer 29

Propanolol Atenolol Reduce O2 demand by decreasing cardiac workload

Question 30

What receptors do Propanolol and Atenolol work at

Answer 30

Propanolol - Non-selective Beta1 and beta2 antagonists Atenolol - Cardioselective Beta1 antagonist

Question 31

What are the side effects of beta-adrenoceptor antagonists

Answer 31

``` Hypotension Bradycardia Bronchoconstriction Hyperlipidaemia Depression Fatigue reduced libido ```

Question 32

What is the aim of calcium channel blocker drugs

Answer 32

Block entry of Ca2+ into muscle cells, reducing myocardial contractility, electrical impulse propagation and vascular tone

Question 33

Name some cardiac favouring calcium channel blockers

Answer 33

Diltiazam | Verapamil

Question 34

Describe the mechanism of cardiac favouring calcium channel blockers

Answer 34

Decreased SA node auromaticity and AV node conduction, resulting in decreased HR and decreased myocardial contractility

Question 35

Name some vessel favouring calcium channel blockers

Answer 35

Nicardipine | Nifedipine

Question 36

Describe the mechanism of vessel favouring calcium channel blockers

Answer 36

Relax blood vessels (arterial vasodilation) therefore decreased BP (workload) and increased coronary artery perfusion (increased oxygen supply)

Question 37

What are the potential side effects of calcium channel blockers

Answer 37

``` Hypotension AV block Bradycardia Constipation Gastric Distress ```

Question 38

What is the main surgical procedure after a myocardial infarction

Answer 38

Angioplasty

Question 39

What is an angioplasty

Answer 39

When you use a stent and open it to open the block with a mesh ting