Treatment of Angina

Question 1

What shrinks the window that allows for coronary filling?

Answer 1

Shortening diastole by increasing heart rate, increased ventricular EDP via aortic valve stenosis and reduced diastolic arterial pressure via mitral or aortic valve incompetence.

Question 2

Describe different ways coronary ischaemia and infarction arise

Answer 2

Coronary ischaemia is usually due to atherosclerosis. Sudden ischaemia that may result in cardiac infarction is usually caused by thrombosis. Coronary spasms can cause variant angina.

Question 3

On a cellular level what results from ischaemia?

Answer 3

Cellular calcium overload due to the decreased oxygen. This may cause cell death and dysrhythmias.

Question 4

What is Angina Pectoris

Answer 4

Chest pain usually due to inadequate supply of oxygen to the heart which typically produces severe and crushing pain

Question 5

Describe the characteristic distribution of the pain of angina pectoris

Answer 5

Often retrosternal or left side of chest and can radiate to left arm, neck, jaw and back. It is brought on by exertion, cold or excitement. It is thought that a build up of local factors (adenosine, potassium ect) due to lack of blood washing them away or increased metabolic activity.

Question 6

What are the three types of angina?

Answer 6

Stable, unstable and Variant (Prinzmetal)

Question 7

Describe features of stable angina?

Answer 7

Predictable chest pain on exertion and is caused by a fix narrowing around the arteries

Question 8

Describe features of unstable angina

Answer 8

Occurs at rest with less exertion. It is associated with a thrombus around a ruptured atheroma but without complete occlusion of vessel (similar to MI)

Question 9

Describe features of Variant angina?

Answer 9

This is uncommon and caused by coronary artery spasm. It is not completely understood but sometimes associated with atherosclerosis

Question 10

Describe the treatments to reduce chest pain symptoms

Answer 10

Beta-blockers, Nitrates, Calcium channel antagonists, Nicorandil, Ivabradine and Ranolazine

Question 11

What are the treatments to prolong survival

Answer 11

Bet-blockers, Aspirin, Statins, angiotensin converting enzyme inhibitors and angiotensin 2 receptor blockers

Question 12

Describe in more detail how you treat symptoms of angina

Answer 12

Can offer short acting nitrate for preventing/treating episodes of angina. Offer a first line treatment (usually beta blockers but can be calcium channel blocker)

Question 13

Describe what you can do if beta blockers are not optimal?

Answer 13

You can add a calcium channel blocker. If neither are effective then other drugs may be used.

Question 14

Describe how antianginal drugs work?

Answer 14

Mainly they work by decreasing the metabolic demand of the muscle. Organic nitrates, nicorandil and calcium antagonists are vasodilators which decrease preload and afterload. Beta blockers and Ivabrandine slow down the heart which decreases metabolic demands.

Question 15

Name two examples of organic nitrates

Answer 15

Glyceryl trinitrate and isosorbide mononitrate.

Question 16

How do organic nitrates work?

Answer 16

They are powerful vasodilators. They are metabolised to nitric oxide and relax smooth muscle, act on veins to decrease preload and also causes dilation of collateral coronary vessels which improves distribution of coronary blood flow to ischaemic areas.

Question 17

High doses of organic nitrites can cause what?

Answer 17

It can effect arteries and therefore decreasing afterload, this is more likely to be given in surgical or hospital settings.

Question 18

What are some of the clinical uses of nitrates in angina?

Answer 18

For stable angina - It can be prevented by sublingual glyceryl trinitrate shortly before exersion or isosorbide mononitrate long before.
Unstable angina - Intravenous glyceryl trinitrate.
Acute heart failure - IV GTN,
Chronic heart failure - Isosorbide mononitrate with hydralazine in African American patients.

Question 19

What are the unwanted side effects of organic nitrates?

Answer 19

Headaches and postural hypotension

Question 20

Describe clinical features of beta blockers?

Answer 20

It is the first line treatment in the prophylaxis and treatment of stable and unstable angina. It decreases cardiac oxygen consumption by slowing heart by decreasing sympathetic innervation. Can also have antidysrhythmic action.

Question 21

Name two examples of beta blockers?

Answer 21

Bisoprolol and atenolol

Question 22

What are the action of the calcium channel blockers?

Answer 22

They prevent the opening of the voltage gated L-type calcium channels to block calcium entry and prevent muscle cell depolarisation

Question 23

What are the two main types of calcium channel blockers?

Answer 23

Dihydropyridine derivates (amlodipine) and rate-limiting (verapamil)

Question 24

What are the effects of calcium channel blockers?

Answer 24

It has vasodilator effects mainly on resistant vessels which reduces afterload and dilates coronary vessels

Question 25

What is specific about rate limiting CCBs?

Answer 25

Verapamil and diltiazem can reduce and impair AV conduction and myocardial contractility, therefore effects the heart as well as vasculature

Question 26

What are the clinical uses of CCBs of angina?

Answer 26

Amlodipine or lercanidipine are safe in patients with HF so can be used instead of BBs in variant angina or along side BB in most angina. Veramapil and Diltiazem are contrainticated in HF, bradycardia, AV block or with BB (because both BB and rate limiting CCBs slow HR)

Question 27

What are the side effects of CCBs?

Answer 27

Headaches, constipation and ankle oedema

Question 28

Describe the clinical uses of CCBs that are not for angina

Answer 28

Mainly verapamil is used in Antidysrhythmics - It slows ventricular rate in rapid AF and prevents recurrence of supraventricular tachycardia, however no effect on ventricular arrhythmias.
Hypertension - Mainly amlodipine or lercanidpine

Question 29

Name and describe potassium channel activators

Answer 29

Nicorandil. It combines activation of potassium channels with nitrovasodilator actions causing hyperpolarisation of smooth muscle (meaning stronger signal is needed to depolarise muscle) However causes headaches, flushing and dizziness. Used in patients who remain symptomatic despite other treatment

Question 30

Describe the effects of Ivabradine

Answer 30

Inhibits F-type sodium channels in the heart, reducing cardiac pacemaker activity and inhibiting heart rate.

Question 31

Describe the effects of Ranolazine?

Answer 31

Unique anti-anginal medication which is used as a last resort