26 CHD

Question 1

what is the difference between a heart attack and cardiac arrest

Answer 1

cardiac arrest is an electrical problem and they will be unconscious

while a heart attack is a circulation problem the person will probably be conscious

Question 2

what is atherosclerosis

Answer 2

deposition of fatty plaques in coronary arteries

Question 3

what does atheroma do

Answer 3

narrowing of the arteries lumen

Question 4

what is angina

Answer 4

angina is a symptom of CHD which is where there is insufficient oxygen supply to myocardium caused by ischaemia

pain characterized by pain in chest arm or neck

Question 5

what is the difference between stable and unstable angina

Answer 5

stable
predictable pain normally on exertion
almost always caused by atheroma

unstable
pain on less and less exertion or at rest
normally caused by ruptured atheroma

Question 6

what is varient angina

Answer 6

artery spasm, associated with atheroma

Question 7

what is microvascular angina

Answer 7

not always due to atheroma, pain often more severe

may not respond to normal treatments for angina

Question 8

what are myocardial infactions also termed

Answer 8

acute coronary syndrome

Question 9

what are myocardial infarctions caused by

Answer 9

coronary artery block by rupture of atheroma and thrombus formation

loss of oxygen to the area of heart supplied by the blocked artery leading to a prolonged loss of oxygen, irreversible cell death.

Question 10

what is embolism

Answer 10

A blood clot that forms in a blood vessel in one area of the body, breaks off, and travels to another area of the body in the blood

Question 11

how might an embolism form

Answer 11

atheroma
thrombus
ebolism

Question 12

how do we diagnose a myocardial infarction

Answer 12

the symptoms are similar to angina attack

• palor
• pain
• etc

Traditionally 3 factors used

• patient history of chest pain
• ECG changes
• Cardiac biomarkers

Troponin >99% then classified as Myocardial infarction

Question 13

How are MI classified

Answer 13

If St segment is elevated then termed STEMI

if St segment normal then classed NSTEMI

Question 14

what drugs are used in CHD or ACS

Answer 14

Acute - Organic Nitrates

Prophylatic

• Organic nitrates
• Beta blockers
• Calcium Channel Blockers
• Anti-thrombolytic and anti platelet agents
• ACE inhibitors

Question 15

what does glyceryl trinitrate do

Answer 15

relaxation of smooth muscle by liberation of nitric oxide and subsequent generation of cGMP

Dilate coronary arteries, re-distribute blood to ischaemic region

reduce cardiac oxygen consumption

prevent or relieve coronary spasm

Question 16

what are the indications of Glyceryl trinitrate

Answer 16

Angina
Heart failure
Extravasation
Anal Fissure

Question 17

what is the mechanism of action of glyceryl trinitrate

Answer 17

releases nitric oxide in the blood stream, produces cGMP in smooth muscle causing relaxation of all blood vessels including collateral arteries

Question 18

what are the disadvantages of organic nitrates

Answer 18

prone to development of tolerance

action is short

shelf life short

Question 19

what are calcium channel blockers

Answer 19

vasodilators also reduce heart rate and force of contraction

Question 20

what do vasodilators

Answer 20

dilate collateral arteries

reduce oxygen demand on heart, dilate coronary arteries

Question 21

what are the most common calcium channel blocker

Answer 21

diltiazem and verapamil

Question 22

in coronary vasospasm what is commonly used

Answer 22

dihydropyridines

Question 23

what should be avoided in angina

Answer 23

nifedipine

Question 24

what are some side effects of CCB

Answer 24

include postural hypotension, flushing, constipation,

Question 25

what is the major side effect of nifedipine

Answer 25

increases mortality following MI

Question 26

what beta blockers should be used in heart failure and post MI

Answer 26

carvedilol and bisoprolol

Question 27

what do beta blockers do

Answer 27

reduce oxygen and demand of the heart by inhibiting sympathetic drive to heart

Question 28

describe the cardioselective properties of beta blockers

Answer 28

little effect on resting heart rate, CO, or arterial pressure

reduce effect of exercise or excitement on the heart due to lower sympathetic drive and effect so lower oxygen demand by heart

Question 29

what is percutaneous coronary intervention or PCI

Answer 29

catheter inserted in femoral or radial arteries, stents placed in narrow coronary artery

stent is expanded increasing arterial diameter and blood flow

Question 30

On first presentation of chest pain what should be done

Answer 30

check last episode of chest pain

eliminate non cardiac pain

assess for ACS symptoms

e. g.
- chest pain longer than 15min
- pain associated with nausea, vomiting, sweating, breathlessness or haemodynamic instability
- new onset of deteroiation of stable angina or reoccuring pain not on exertion longer than 15 mins

Question 31

when should we refer as an emergency

Answer 31

acs suspected

have chest pain or 12 lead ECG abnormal

Question 32

refer for same day assessment

Answer 32

no reasons for emergency
pain in last 12 hours but now pain free and normal ECG
last pain episode was 12 - 72 hours ago

Question 33

how do we treat NSTEMI

Answer 33

aspirin 300 mg until clinical decisions made

high risk patients angiogram with follow on PCI angioplasty if required

dual antiplatelet therapy, prasugrel/ticragrelor + aspirin

low risk dual antiplatelet ticagrelor with aspirin

Question 34

how do we initially treat stemi

Answer 34

aspirin 300 mg until clinical decisions made

most common reperfusion therapy - noramlly PCI

dual antiplatelet therapy for 12 months