Myocardial Infarction

Question 1

What is a STEMI

Answer 1

EMERGENCY

caused by a complete occlusion of a coronary artery

Question 2

What is an NSTEMI

Answer 2

MI caused by partial occlusion of an artery

Question 3

What are the symptoms of an MI

Answer 3

Central crushing pain 
Radiates to arms, jaw and neck. Most commonly to the left 
10/10 pain (in diabetics reduced) 
Not relieved by resting, slightly reduced by GTN BUT not in STEMI 
Nausea 
Vomiting 
Sweating 
Pallor 
Palpitations 
May be SOB or tachypnoeic

Question 4

What are the signs of an MI

Answer 4

Can vary from patient to patient 
Low grade fever 
Pale 
Cool clammy 
Hypotension/hypertension 
S3 and s4 may be present 
Could be signs of CCF

Question 5

Which investigations are needed

Answer 5

Bloods
- troponin –> trop 1 and creatinine elevated in myocyte damage
- cardiac enzymes
- FBC, U&Es (kidney function, anaemia)
- glucose and lipids (risk factors)
- amylase and lipase levels to rule out pancreatic causes
- clotting
- CRP
ECG - differentiates between STEMI, NSTEMI and unstable angina
CXR - to rule out if due to HF

Question 6

What does an ECG show in an NSTEMI

Answer 6

ST depression

T wave flattening or inversion

Question 7

What are the different ST depressions

Answer 7

Up sloping - non specific for myocardial ischaemia

Horizontal or down sloping of 0.5mm or more in 2 or more leads indicates myocardial ischaemia

Question 8

What is the initial management for an MI

Answer 8

IV diamorphine
Oxygen if says lower than target 15L through non rebreathe and titrate down
IV nitrates - titrate to pain and keep systolic BP above 100mmHg
Aspirin 300mg PO

Question 9

What is the management for a STEMI

Answer 9

PPCI - within 2hrs from onset of chest pain
If PCI not possible within 2 hrs, fibrinolysis (streptokinase and alteplase) followed by rescue PCI
Prasugrel and aspirin to prevent atherthrombotic events in PCI

Question 10

What is the treatment for an NSTEMI

Answer 10

High risk patients - same as a STEMI 
Low risk - drug therapy 
1. analgesia - morphine 
2. anti-ischaemic
- beta blockers 
- nitrates 
- ace inhibitors 
- calcium channel blockers 
- statins 
3. anti-thrombotic 
- short term anticoagulant - fondaparinux, dalteparin 
4. Anti-platelet 
- aspirin 
- Clopidogrel

Question 11

What is the long term management after an MI

Answer 11

Pts with stents - aspirin and clopidogrel. Aspirin for life and clopidogrel stopped after 1 yr
Beta blocker
Ace inhibitor - ramipril
Statin - atorvostatin

Manage lifestyle factors - diet, exercise
Improve diabetic control
Cardiac rehab
Not allowed to drive for 4 weeks must inform DVLA
Smoking cessation
Cut down alcohol

Question 12

What is the assessment called for NSTEMIs

Answer 12

GRACE assessment

Question 13

What are the complications of a STEMI

Answer 13

SPREAD
S - Sudden death
P - Pericarditis/Pump failure 
R - Rupture of papillary muscles or septum
E - Embolism 
A - Anuerysm/Arrhythmia 
D - Dresslers syndrome

Question 14

What is dresslers syndrome?

Answer 14

A secondary form of pericarditis that occurs after injury to the heart or pericardium 
presents with 
Fever
pleuritic pain
Pericarditis 
Pericardial effusion

Question 15

What is the pathophysiology behind acute coronary syndrome

Answer 15

Rupture of atherosclerotic plaque in coronary arteries
platelet aggregation and adhesion
Thrombus formed causing less flow through the blood vessel
Less oxygen gets to the myocardium –> ischaemia

Question 16

How can NSTEMI and Unstable angina be differentiated?

Answer 16

Check Troponin I 2 hours after onset of pain
NSTEMI - positive troponin
UA - negative troponin

Question 17

What type of arrhythmias may occur as a complication of acute coronary syndrome

Answer 17

Ventricular fibrillation
Ventricular Tachycardia
AV block

Question 18

What can rupture after a STEMI

Answer 18

Left ventricle - causes tamponade and death
Ventricular septum - ventricular septal defect
Papillary muscle - severe mitral regurg