Acute Coronary Syndromes 1 Flashcards
Define ACS, STEMI, NSTEMI & unstable angina. Initial mangement & management of STEMI
What is ACS?
Spectrum of conditions which includes STEMI, NSTEMI and unstable angina
What does ACS result from?
ACS (e.g. STEMI, NSTEMI, unstable angina) result from formation of a thrombus on atheromatous plaque in a coronary artery
Definitive diagnosis of ACS is based on the following 3 things
ECG changes
Clinical presentation
Measurement of biochemical cardiac markers
What is a STEMI usually caused by
Complete and persistent blockage of coronary artery resulting in myocardial necrosis with ST-segment elevation seen on ECG
What is NSTEMI caused by
Partial or intermittent blockage of artery, which usually results in myocardial necrosis
ECG may show ST-segment depression, T-wave inversion, or may be normal
What is unstable angina caused by
Partial or intermittent blockage of artery which does not result in myocardial necrosis
ECG may show ST-segment depression, T-wave inversion, or may be normal
How would you differentiate between NSTEMI and unstable angina?
The partial or intermittent blockage of the coronary artery usually results in myocardial necrosis in NSTEMI, not in unstable angina
A high-sensitivity blood test for serum troponin
Troponin as a differentiation test for NSTEMI and unstable angina
- High sensitivity blood test for serum troponin are used to differentiate these
- Troponin elevated in NSTEMI due to the myocardial necrosis, but is normal in unstable angina
What are the non drug treatment options available following an ACS
- Revascularisation procedures e.g. percutaneous coronary intervention (PCI) or coronary arrest bypass graft (CABG)
- These help restore blood flow when it is limited or blocked
- These are often appropriate alongside drug treatment for pt with ACS
Initial management - pain relief in ACS
ASAP: GTN (sublingual or buccal)
IV opioids e.g. morphine may be administered, esp if acute MI is suspected
Aims of initial management of ACS
- Provide supportive care & pain relief & prevent progression of cardiac injury
- Start as soon as ACS suspected, but treatment should not delay transfer to hospital
- Pain relief: GTN (sl or buccal), IV opioids esp if acute MI
- Loading dose of aspirin ASAP (if given before arrival at hospital, a note saying it has been given should be sent with pt)
- Only offer other anti platelets once in hospital according to their diagnosis and RF
- Do not routinely administer oxygen but monitor pt oxygen saturation (ideally before admission) and offer supplemental oxygen is indicated
- Monitor all pt admitted in hospital for hyperglycaemia (if BG>11mol/L, give insulin)
Aims of management of STEMI
Restore adequate coronary blood flow ASAP and reduce mortality
Management of STEMI - reperfusion therapy
- Immediately assess eligibility (irrespective of age, ethnicity or sex) for coronary reperfusion therapy
- Deliver coronary reperfusion therapy (primary PCI or fibrinolysis) ASAP in eligible patients
- Do not use level of consciousness after cardiac arrest caused by suspected acute STEMi to determine whether pt is eligible for coronary angiography (with follow on PCI if indicated)
What is coronary angiography
- Performed to detect obstruction in coronary arteries
- Uses a special dye (contrast material) and x-rays to see how blood flows through the arteries in your heart
- If blocked, follow up PCI may be indicated to help restore blood flow
Initial drug therapy in acute STEMI
- Single loading dose of 300mg aspirin ASAP unless evidence of allergy
- Do NOT offer routine glycoprotein IIb/IIIa inhibitors or fibrinolytic drugs before arrival at catheter lab to pt with acute STEMI who have primary PCI planned