Atherosclerosis: Angina and Acute Coronary Syndromes Flashcards
What is acute coronary syndrome?
any group of symptoms attributed to the obstruction of the coronary arteries
- non ST elevated myocardial infarction
- ST elevated myocardial infarction
- unstable angina
What is a myocardial infarction?
- caused by a blood clot
- usually forms inside a coronary artery
- clot may form if there is atheroma (plaques) inside the artery
What enzyme can be detected in the case of a MI?
troponin increased when cells are damaged due to lack of oxygen
troponin I and T become detectable in serum 3-6 hours after, peak 12-24 hours and raised for 2 weeks
troponins tested for 6-12 hours after onset of pain
What are the two types of MI?
- ST elevated
- non ST elevated
ST: beginning of ventricular repolarisation
Why are death rates higher in the first few hours after a cardiac event?
ventricular tachycardia and arrhythmias
Describe the two types of plaque in arteries.
- stable plaque: arterial blood flow obstruction and symptoms of angina
- unstable plaque: prone to rupture and form a thrombus
What are risk factors of MI?
- tobacco smoke
- high cholesterol
- high BP
- physical inactivity
- obesity
- diabetes
- increased age
- male sex
- family history
- race
Symptoms of acute coronary syndrome?
- sudden onset ‘crushing’ chest pain
- originates in centre of chest then radiates to arms, neck or jaw
- associated with sweating and shortness of breath
- difficult to distinguish between heart related chest pain and GORD
What is aspirin?
antiplatelet - prevents clots from being formed
What is treatment of STEMI?
- aspirin 300mg
- coronary refusion therapy: primary percutaneous coronary intervention with an additional antiplatelet agent (ticagrelor or prasugrel) OR fibrinolysis (reteplase or tenecteplase)
- coronary angiography (dye)
- medical management and secondary prevention
- pain relief, anti emetics, glycaemic control
What are ticagrelor and prasugrel? What is an alternative?
antiplatelets
ticagrelor has faster onset of action
cangrelor is not given orally, usually used in hospital
What is secondary prevention of STEMI?
- aspirin 775mg lifelong
- if stent: dual antiplatelet therapy (clopidogrel)
- PPI (lansoprazole) may be required to reduce GI side effects (aspirin)
- beta blockers and ACEi can reduce mortality
- aldosterone antagonists for those with HF
- lipid lowering treatment
- low dose rivaroxaban for prevention of antithrombotic events
What is unstable angina?
- symptoms of MI but not sufficient troponin rise
What is treatment for NSTEMI and unstable angina?
- aspirin loading dose 300mg
- ticagrelor 180mg loading dose
- consider antiplatelets: eptifibatide and tirofiban in patients undergoing coronary angioplasty
- antithrombin therapy: fondaparinux or unfractioned heparin
- coronary angiography with or without PCI or CABG
- pain releif and anti emetics
What is secondary prevention of NSTEMI and unstable angina?
- dual antiplatelet therapy
- lipid lowering medication statins
- ACEi
- beta blockers
