Treatment of ischemic heart disease

Question 1

What is ischemic heart disease?

Answer 1

A consequence of inadequate coronary perfusion relative to
myocardial demand.

Question 2

What are the causes of myocardial ischemia

Answer 2

Pre-existing (“fixed”) atherosclerotic occlusion of the coronary
arteries
* Acute plaque change with superimposed thrombosis and/or
vasospasm

Question 3

What is angina pectoris

Answer 3

Characteristic chest pain (burning or heavy discomfort behind the sternum), of duration <
15 minutes, due to myocardial ischaemia, usually occurring on exercise and relieved by
rest

Question 4

3 steps in the tx of angina pectoris

Answer 4

1. B-Blocker: Atenolol
2. Add 2nd agent: Long acting calcium channel blocker: Amlodipine
3. Add 3rd agent: Isosorbide mononitrate/dinitrate

Question 5

What is the Long-term prophylaxis for thrombosis/cardiovascular events?

Answer 5

Aspirin, oral, 150 mg daily.
HMGCoAreductase inhibitor (statin)
Simvastatin / Rosuvastatin
Atorvastatin

Question 6

Tx for relief of angina

Answer 6

Nitrates, short acting e.g.:
Isosorbide dinitrate, sublingual, 5 mg

Question 7

Pt counselling points regarding Tx for angina relief (4)

Answer 7

o Maybe repeated if required at 5‐minute intervals for 3 or 4 doses.
o Instruct patients to keep the tablets in the airtight and lightproof container in
which they are supplied.
o Instruct patients that nitrates are not addictive.
o Instruct patients to use prophylactically, before activities which may provoke
angina.

Question 8

List 3 organic nitrates

Answer 8

• Glyceryl trinitrate
• Isosorbide mononitrate
• Isosorbide dinitrate

Question 9

What are the actions of nitrates?

Answer 9

Relax smooth muscle, especially vascular smooth muscle (also
oesophageal and biliary)
* Relax veins, reduction in central venous pressure (reduced preload)
* Reduced stroke volume = venous pooling on standing, postural hypotension and dizziness

Question 10

T/F: Therapeutic doses have less effect on
small resistance arteries than on veins
but marked effect on larger muscular
arteries.

Answer 10

T

Question 11

Effects of organic nitrates on coronary arteries

Answer 11

Direct dilation of coronary
arteries – increased coronary flow

Question 12

effects of organic nitrates on myocardial oxygen consumption

Answer 12

Decreased myocardial oxygen consumption (decreased pre- & afterload)

Question 13

Effects of organic nitrates on coronary sinus blood

Answer 13

Increased oxygenation of coronary sinus blood

Question 14

Effects of organic nitrates on collateral vessels

Answer 14

dilation of collateral vessels

Question 15

State 3 anti-anginal actions of organic nitrates

Answer 15

• Reduced cardiac work – reduced pre- & after load = reduced oxygen
  demand
• Redistribution of coronary flow to ischaemic areas via collaterals
• Relief of coronary spasm

Question 16

Adverse effects of nitrates

Answer 16

Main adverse effects are direct consequence of pharmacological action
(type A)
* Postural hypotension and headache – tolerance to these effects
develops quickly

Question 17

T/F: Glyceryl nitrate is rapidly inactivated by hepatic metabolism

Answer 17

T

Question 18

ROA and onset of action of glyceryl trinitrate

Answer 18

sublingual – onset of action = few minutes
converted to di- and mononitrates

Can also be absorbed through the skin – transdermal patch

Question 19

Duration of action of glyceryl trinitrate

Answer 19

30min

Question 20

Organic nitrates are highly ____________________
so they evaporate quickly when opened.

Answer 20

Volatile

Question 21

Which formulation of organic nitrates is more stable?

Answer 21

Spray

Question 22

Isosorbide mononitrate pharmacokinetics, ROA and dosage instructions

Answer 22

Isosorbide mononitrate: longer acting, absorbed and metabolised
more slowly.
* Route of administration: oral
* Take twice daily in the morning (8:00) and at lunch (14:00) to allow
for the nitrate free period (to avoid tolerance)

Question 23

Least lipophilic cardio-selective b-blocker

Answer 23

Atenolol - loses selectivity at high doses

Question 24

Excretion and frequency of dose of atenolol

Answer 24

Excreted mainly unchanged in the urine – may accumulate in kidney
failure

give once daily

Question 25

T/F: Atenolol is affected by liver disease, or drugs inhibiting hepatic metabolism or conditions affecting hepatic blood flow

Answer 25

F. It is not affected

Question 26

contraindications of atenolol (4)

Answer 26

Contraindicated in heart block, symptomatic heart failure (unless or until signs are controlled), sinus bradycardia, cardiogenic shock

Question 27

Cautions of atenolol 2

Answer 27

renal failure, pregnancy

Question 28

Drug interactions with atenolol

Answer 28

Digoxin, verapamil, diltiazem additive depressant effects on the heart; * Insulin/oral antidiabetics, increased risk of hyperglycaemia and masking of hypoglycaemia (except sweating)

Question 29

adverse effects of atenolol

Answer 29

Decreased HDL, increased TGs and glucose utilization impairment, bronchospasm (asthma, high doses)

Question 30

4 characteristics of unstable angina

Answer 30

angina at rest or minimal effort * angina occurring for the first time, particularly if it occurs at rest * prolonged angina > 10 minutes, not relieved by sublingual nitrates * the pattern of angina accelerates and gets worse

Question 31

5 short term Tx goals for acute coronary syndrome

Answer 31

Early restoration of blood flow to the infarct-related artery to prevent infarct expansion (in the case of MI) or prevent complete occlusion and MI (in UA); * Prevention of death and other MI complications; * Prevention of coronary artery re-occlusion * Relief of ischemic chest discomfort.

Question 32

3 long term Tx goals for acute coronary syndrome

Answer 32

Control of atherosclerosis risk factors, * Prevention of additional MACE, including reinfarction, stroke, and HF * Improvement in quality of life.