Myocardial Infarctions and Cardiac arrest Flashcards
What does STEMI stand for?
ST Elevation Myocardial Infarction
What does NSTEMI stand for?
None ST Elevation Myocardial Infarction
Whats the difference physiologically between a STEMI and NSTEMI?
STEMI involves total occlusion of the blood vessel whilst NSTEMI is only partly occluded by the thrombus plaque
What is the triggering factor in both?
Acute plaque rupture leading to occlusion or partial occlusion of the vessel
What factors influence likely hood of a plaque rupture?
Younger, Fattier, thiner, Increased intraluminal pressure, mechanical injury all increase rupture threat
Which two chemical are released by the platelets to attract other factors and more platelets to the site?
ADP and Thromboxane
STEMI Diagnosis- History
Sever crushing central chest pain
More prolonged GTN doesn’t relieve
Nausea Sweaty Pallor
STEMI Diagnosis- ECG
ST elevation, T wave inversion, Q Wave
Left bundle Branch MI ECG
Prolonged ST phase V1-V4
STEMI Diagnosis- Troponin
Don’t really have time to wait on the results so not really part of the diagnosis
What is the double antiplatelet therapy used in MI
Aspirin + Clopidogrel
Ticagrelor is more potent that clopidogrel used if no threat of bleeding
If the patient is more than 120mins away from a hospital with angioplasty and stent lab what happens?
Given Thrombolysis but still taken to a hospital with ability to do angioplasty and stenting; either for emergency stenting if thrombolysis failed or routine a while after if thrombolysis worked.
6 steps in treating MI
Analgesia- Diamorphine IV Anti-emetic IV Aspirin + Tricagrelor/ clopidogrel GTN if BP> 90 mmHg Oxygen if hypoxic Primary Angioplasty
Post MI complications
Death, Structural, functional and arrythmic
Structural complications as a results of an MI
Cardiac rupture- fatal untreatable
Mitral Valve Regurgitation- papillary muscle damaged
Septal defect- treated with surgery to block hole
Arrythmic complications of an MI
Ventricular fibrillation- rapid clustered disordered ST, ventricles don’t work DEFIB required
Functional complications
Acute ventricular failure- left right biventricular
Chronic cardiac failure
Cardiogenic Shock
NSTEMI Diagnosis history
Typical heart pain similar to MI crushing radiating etc
NSTEMI Diagnosis- ECG
May be normal
ST depression is sign of ischaemia
Troponins use in NSTEMI diagnosis
Detects the higher risk patients as spikes when plaque ruptures so several spikes over several test shows risk of plaque rupturing multiple times
Also detects minor areas of ischaemia due to break of emboli
Treatment in NSTEMI
Aspirin+ Ticagrelor/Clopidogrel
Low molecular weight heparin
Beta Blockers if NO bradychardia or hypotension
Bypass or angioplasty + stenting
What other conditions is troponin elevated in?
Renal failure hypertensive crisis, PE, sepsis, post-AF pericarditis, Stroke/TIA
Type 1 MI
Sudden onset of symptoms
Major ECG changes
Higher troponin but falls
Severe CAD
Type 2 MI
Chest Pain
ECG changes
Smaller troponin but constant
No CAD
Cardiac Arrest
Effective cessation of the heart
Cardiac Arrest treatment
Increase O2 saturation, clear airway improve breathing
Transfusion, treat anaemia
Heart Rate- Atropine or B stimulant epinephrine
How to increase stroke volume in cardiac arrest
Pre load- IV fluids raise legs
Contractility- Treat cause , PCI for MI
Excess after load- use vasodilators
Reduced after load- e.g. septic shock use vasoconstrictors
Main thrombolysis drug used
TNKase less cerebral bleeding risk
