Myocardial Infarction Flashcards Preview

Cardiovascular > Myocardial Infarction > Flashcards

Flashcards in Myocardial Infarction Deck (26):
1

What is a myocardial infarction?

A heart attack

When a blockage stops blood flow through the coronary arteries of the heart, meaning that the heart muscles are starved of oxygen and eventually die.

2

What two types of MI can be distinguished on an ECG?
Draw the ECG of each type.

ST elevation (the ST segment is raised)

Non-ST elevation (the ST segment is normal

3

What are the symptoms of an MI?

Cardiac chest pain:
- gradual onset
- unremitting
- severe (usually)
- occurs at rest
- radiates to left arm, jaw, neck

Breathlessness
Nausea & vomiting

4

What are the signs of an MI?

Sweating
Impending sense of doom
High BP
Signs of heart failure

5

Where to 1/3 of all MIs occur?

In bed at night

6

What are the causes of MI?

Rupture of an atherosclerotic plaque that leads to formation of thrombus

Coronary vasospasm
Drug abuse
Dissection of coronary artery
Thoracic aortic dissection

7

What could cause dissection of coronary arteries?

A disorder of connective tissue, such as Marfan's syndrome

8

What are the risk factors for MI?

Male gender
Age
Family history of CHD
Hyperlipidaemia
Diabetes
Renal failure
L ventricular systolic dysfunction
Lifestyle factors

9

What lifestyle factors increase MI risk?

Smoking
High cholesterol
Obesity
Sedentary lifestyle
Type A personality: more highly strung people

10

What is the pre-hospital management of a patient with a suspected MI?

Call an ambulance

Paramedics do an ECG: if it shows ST elevation they contact the PCI unit in advance so they can prepare for the patient

Give 300mg aspirin

Give pain relief: morphine

11

What does STEMI stand for?

ST elevation MI

12

What does NSTEMI stand for?

Non-ST elevation MI

13

Which is worse? A STEMI or a NSTEMI?

A STEMI

14

What is the acute management of a confirmed STEMI?

Attach ECG to monitor heart

Oxygen therapy if hypoxic

Continue pain relief: narcotics & nitrates

Restore coronary perfusion:
PCI or fibrinolysis

Anticoagulation medication

Beta-blockers

ACE inhibitors

15

What is troponin?

A complex of three regulatory proteins:
- Troponin C
- Troponin I
- Troponin T

16

What does troponin do?

Integral to muscle contraction in skeletal & cardiac muscle

17

What do raised troponin levels mean?

Cardiac muscle cell death
Troponin is released into the blood upon cardiac injury

18

What is PCI?

Percutaneous coronary intervention

Fitting of a stent in the blocked coronary artery to restore blood flow through it

19

Ideally, in what time period should someone with an MI have PCI?

Within 120 mins of first medical contact

20

What is fibrinolysis?

Breaking down the clot

Fibrinolytic drugs:
Streptokinase, ateplase

Drugs that break down the clot

21

Ideally, in what time period should someone with an MI receive fibrinolytic drugs?

Within 30 mins of admission

22

What is the management of a confirmed NSTEMI?

Admit to CCU

ECG while in pain

Give oxygen if hypoxic

Analgesia: narcotics or nitrates

Oral beta blocker: eg. metoprolol

Anticoagulant: aspirin or clopidogrel

Monitor for any changes, such as ST elevation or raised troponin. If these occur consider reperfusion therapy

23

Do raised troponin levels definitely confirm an MI?

No!
Troponin can be raised for other reasons.

So take a history as well to confiorm MI

24

What reasons can troponin be raised?

Myocardial necrosis
Gram -ve sepsis
Myocarditis
Heart failure
Arrhythmias
Cytotoxic drugs

25

What tests should be done in a suspected MI?

ECG

Bloods:
FBC, U&E, glucose, lipids
Troponin levels are raised if there is myocardial necrosis


CXR: look for cardiomegaly

26

What is the subsequent management of MI patients? After the acute event is over.

Bed rest with continuous ECG monitoring

Thromboembolism prophylaxis until fully mobile

Prescriptions to take home:
- Warfarin (if large anterior MI)
- Aspirin
- B-blockers
- ACEi
- Statin

Modify lifestyle