Acute coronary syndrome Flashcards
What is the spectrum of conditions included in Acute Coronary Syndrome (ACS)?
Myocardial infarction (MI) with or without ST-segment elevation (STEMI or NSTEMI) and unstable angina.
What causes Acute Coronary Syndrome (ACS)?
The formation of a thrombus on an atheromatous plaque in a coronary artery.
What is myocardial infarction (MI)?
Necrosis of myocardial tissue due to ischaemia, usually caused by blockage of a coronary artery by a thrombus.
What causes STEMI and how is it characterized on an ECG?
STEMI is caused by a complete and persistent blockage of a coronary artery, leading to myocardial necrosis. It is characterized by ST-segment elevation on the ECG.
What distinguishes NSTEMI and unstable angina from STEMI?
NSTEMI and unstable angina are caused by partial or intermittent blockage of a coronary artery. NSTEMI results in myocardial necrosis, while unstable angina does not. ECG changes may include ST-segment depression, T-wave inversion, or may be normal.
How are NSTEMI and unstable angina differentiated?
High-sensitivity blood tests for serum troponin are used to differentiate between NSTEMI and unstable angina.
STEMI:
In STEMI, the ST-segment on an ECG is elevated, indicating a more severe and potentially larger heart attack, which is often associated with a higher troponin release.
NSTEMI:
In NSTEMI, the ST-segment is not elevated, but there is still evidence of heart muscle damage, as indicated by elevated troponin levels.
Troponin is a protein released into the bloodstream when heart muscle is damaged, and its presence and levels are used to diagnose heart attacks.
What causes stable angina?
Stable angina is typically caused by coronary artery disease and occurs predictably with physical exertion or emotional stress, relieved by rest or sublingual glyceryl trinitrate.
What is unstable angina?
Unstable angina is new onset angina or an abrupt deterioration in previously stable angina, often occurring at rest. It usually requires immediate medical attention.
What is Prinzmetal’s (vasospastic) angina?
A rare form of angina caused by a spasm in the coronary arteries, typically occurring at rest rather than during activity.
What are revascularization procedures used for in ACS management?
Revascularization procedures like percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) are used to open blocked arteries and improve blood flow to the heart.
What is the first-line pain relief treatment for ACS?
Glyceryl trinitrate (sublingual or buccal) should be administered as soon as possible.
What is the recommended initial antiplatelet therapy for ACS?
A loading dose of aspirin 300mg should be given as soon as possible. If aspirin is given before arrival at the hospital, a note should be sent with the patient.
What should be monitored for all patients admitted to the hospital for ACS?
Hyperglycaemia. Patients with blood-glucose concentrations greater than 11.0 mmol/litre should receive insulin.
What are common thrombolytics used in STEMI management?
Alteplase, reteplase, and tenecteplase are common fibrinolytic drugs.
What second antiplatelet agents are recommended for STEMI patients?
Prasugrel, ticagrelor, or clopidogrel, with the choice depending on the planned intervention and bleeding risk.
What antithrombotic therapy should be given during primary PCI?
Heparin (unfractionated) should be given for radial access. If femoral access is used, bivalirudin is considered.
What second antiplatelet agents are used for unstable angina and NSTEMI?
Prasugrel, ticagrelor, or clopidogrel, with the choice depending on the planned intervention and bleeding risk.
What antithrombin therapy is recommended for unstable angina and NSTEMI?
Fondaparinux sodium should be given, unless the patient is undergoing immediate angiography or has a high bleeding risk. Heparin may be used as an alternative in cases of renal impairment.
What is secondary prevention following acute MI?
Secondary prevention includes drug treatments, lifestyle modifications, and cardiac rehabilitation to reduce the risk of further cardiovascular events.
What are key drug treatments for secondary prevention following MI?
ACE inhibitors or ARBs, beta-blockers (at least 12 months), dual antiplatelet therapy, and statins should be continued indefinitely.
What should be done for a patient with suspected ACS while waiting for hospital admission?
Sit the patient up, administer glyceryl trinitrate or opioid for pain, give aspirin, and perform a 12-lead ECG.
What should be done for patients who do not require hospital admission but have suspected ACS?
Refer for urgent assessment if chest pain is recent (within 12 hours) or for follow-up within 2 weeks for cases without acute symptoms
What is the first-line drug therapy for long-term prevention of stable angina?
Beta-blockers (e.g., atenolol, bisoprolol, metoprolol, propranolol) should be used as first-line therapy for long-term prevention.
What is the alternative to beta-blockers for long-term prevention in stable angina?
A rate-limiting calcium-channel blocker (e.g., verapamil or diltiazem) is an alternative if beta-blockers are contraindicated.
What combination therapy may be considered if beta-blockers alone fail to control stable angina symptoms?
A combination of a beta-blocker and a calcium-channel blocker may be used, but never combine a beta-blocker with a rate-limiting CCB (e.g., diltiazem or verapamil).
What should be considered if beta-blockers and calcium-channel blockers are not tolerated or are contraindicated?
Long-acting nitrates (e.g., isosorbide mononitrate), ivabradine, nicorandil, or ranolazine may be considered either as monotherapy or in combination.
What are the common causes of cardiac arrest?
Cardiac arrest can be associated with ventricular fibrillation, pulseless ventricular tachycardia, asystole, and pulseless electrical activity.
What is the recommended dose and frequency of adrenaline (epinephrine) for cardiac arrest?
Adrenaline (1 in 10,000, 100 micrograms/mL) is given via intravenous injection every 3–5 minutes if necessary.
