Flashcards in Myocardial Infarction Deck (15):
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.
Three types of ACS. What are the differences between them?
Unstable angina: no trop raise, no ECG changes
NSTEMI: trop raise, can have ECG changes but no ST elevation
STEMI: trop raise, ECG changes ST elevation
What are the symptoms of an MI?
Cardiac chest pain:
- gradual onset
- severe (usually)
- occurs at rest
- radiates to left arm, jaw, neck
What are the signs of an MI?
Tachy or bradycardia
Hyper or hypotension
Signs of heart failure (displaced apex, pulmonary and peripheral oedema)
Signs of hyperlipidaemia: xanthalasma on eyes, xanthoma on tendons, corneal arcus
Extra heart sounds S3, S4
What are the causes of MI?
Rupture of an atherosclerotic plaque that leads to formation of thrombus
Dissection of coronary artery (Marfan's?)
What are the risk factors for MI?
Family history of CHD
L ventricular systolic dysfunction
What is the management of a patient with a suspected MI?
ECG to see if STEMI or NSTEMI
Oxygen (only if hypoxic)
Nitrate (GTN spray)
Clopidogrel or other antiplatelet (ticagrelor 180mg)
If STEMI, eligible and within time frame - PCI
If not within timeframe: fibrinolysis with alteplase or streptokinase
If NSTEMI monitor closely, ?fibrinolysis
What is troponin?
Integral to muscle contraction in skeletal & cardiac muscle
What do raised troponin levels mean?
Cardiac muscle cell death
Troponin is released into the blood upon cardiac injury
Ideally, in what time period should someone with an MI have PCI?
Within 120 mins of first medical contact
What is fibrinolysis?
Breaking down the clot
Drugs that break down the clot
Ideally, in what time period should someone with an MI receive fibrinolytic drugs?
Within 30 mins of admission
Do raised troponin levels definitely confirm an MI?
Troponin can be raised for other reasons:
Gram -ve sepsis
What tests should be done in a suspected MI?
FBC, U+E, glucose, lipids, troponin
CXR: look for cardiomegaly