Acute Coronary Syndromes Flashcards
Define Acute Coronary Syndrome
Covers a spectrum of acute cardiac conditions from unstable angins to varying degrees of MI
What indicates a Q-wave infarction
ST elevation
What indicates a Non-Q infarction
ST depression/ T wave inversion
What indicates an unstable angina on an ECG
Normal (can’t detect)
Clinical classification of unstable angina
- Cardiac chest pains at rest and increasing
2. No rise in troponin levels
When can MI be diagnosed on ECG alone
If ST is elevated
When is diagnosis made if there is no ST elevation but MI has happened
After troponin results come in
What are characteristics of a non Q-wave MI
- Poor R wave progression
- Biphasic (inverted) T wave
- ST elevation
Signs of an MI
- Unremitting
- Severe
- Occurs at night
- Sweating
- Breathlessness
- Nausea
Risks that increase MI chances
- Higher age
- Diabetes
- Renal Failure
- Left ventricular systolic dysfunction
How is MI initially managed
- 999!
- if ST elevation is seen by paramedic, transfer to PCI centre
- 300mg aspirin immediately
- Pain relief
How is MI managed in hospitals
- Diagnosis
- Bed rest
- Oxygen therapy
- Narcotics/nitrates
- Aspirin and P2Y12 inhibitor
- Beta-blockers
How is ACS commonly caused
Plaque rupture - arterial thrombosis
or CORONARY VASOSPASM (not common)
What is troponin
Regulates actin:myosin contraction
Why is looking at troponin levels not accurate for MI
- Positive in pulmonary embolism
- Myocarditis
- Arrythmias
- Heart failures
How does aspirin function
- Inhibits COX-1 and COX-2 which produce PROSTAGLANDINS
irreversibly
Role of prostaglandins
Pro-inflammatory - induce clotting
Role of P2Y12
Promotes platelet proliferation
Name three P2y12 inhibitors
Clopidogrel
Prasugrel
Ticagrelor
Problem with P2Y12 inhibtors
Can cause severe bleeding
What are GP11b/IIIa antagonists
Intravenous drugs
What are sued in conjunction with GPIIb/IIIa antagonists
Aspirin and oral P2Y12 inhibitors
Why has the use of GPIIb/IIIa decreased
Oral anti platelet therapy more convenient
When is GPIIb/IIIa still given
In patients taken opiates which are delaying gastric emptying
What are anticoagulants used for
Target formation of thrombin
Inhibit fibrin formation and platelet activation
Why is Fondaparinux better than heparin
Fonaparinux is safer because of low-level of anticoagulation used
What anticoagulant is usually used during PCI
Heparin
When else is heparin used
CABG surgery
What are given to patients with heart failure
Diuretic
ACEI
Beta Blocker
Aldosterone antagonist
When is coronary angiography performed
Patients with troponin elevation or unstable angina
What is the most common revascularisation procedure
CABG
Name drugs that inhibit thrombin
Heparin
Apixaban
Bivalirudin
Rivaroxaban
How is clopidogrel activated/ inactivated
In the liver
What factors effect response to clopidogrel
- Dose
- Age
- Weight
- Disease states (diabetes)
- Drug-drug interactions
- CYP loss of function
Describe the activation of Clopidogrel
Clopidogrel -> 2-oxo-clopidogrel -> R-130964
Describe the activation of prasugrel
Prasugrel -> R-95913 -> R-138727
Describe the mechanism of action of ticagrelor
Inhibits adenosine uptake by cells via the ENT-1 channels in the membrane
Role of adenosine in the blood
Cause vasodilation
Caridoprotection
Anti platelet
Adverse effects of ticagrelor
Bleeding
Rash
Gi disturbances
How is dyspnoea caused by using ticagrelor resolved
Switching to prasugrel and clopidogrel
What is the idiosyncratic effect of ticagrelor
Ventricular pauses
How is an acute STEMI treated
- ECG
- Tropinin/ Glucose count in FBC
- 300mg ASPIRIN
- 180mg Ticagrelor
- Morphine (5-10mg) + metoclopramide (anti-emetic)
- PCI or Fibrinolysis
Non-STEMI treatment
- Low flow O2
- Morphone + Metoclopramide
- GTN spray
- 300mg Aspirin
- 2.5mg Fondaparinux
- Ticagrelor
- IV GTN
- ORAL BISOPROLOL