Management of Acute Coronary Syndrome Flashcards
(97 cards)
What is Angina?
A clinical syndrome caused by insufficient oxygen delivery to the heart muscle, leading to ischemia. It results from an imbalance between increased demand and decreased supply, often due to atherosclerotic plaques in coronary arteries.
What is ischemia?
Restriction of blood flow
What does decreased supply cause?
Coronary plaque perfusion
Decrease perfusion pressure
Decrease arterial oxygen content
What is the most common symptom of an angina?
Constricting discomfort in the front chest; radiating to neck, jaw and left arm.
What does an increase demand cause?
Increase heart rate
Increase pre-load
Increase after-load
Increase contractility
What are the aims of treating angina?
Relieve symptoms,
Prevent or slow disease progression,
Prevent further cardiac events, and improve survival and quality of life.
What are the characteristics of stable angina?
Precipitated by exertion or extreme temperatures, relieved by rest or nitrates, with a set pattern of triggers. It involves long-term management to prevent attacks and reduce the risk of coronary artery disease.
What defines unstable angina?
An acute coronary syndrome characterized by sudden worsening of symptoms, no/minor ECG changes or troponin rise, and less responsiveness to treatment. It can progress to myocardial infarction (MI).
What are Acute Coronary Syndromes (ACS)?
A spectrum of conditions including unstable angina, Non-ST Segment Elevation Myocardial Infarction (NSTEMI), and ST-Segment Elevation Myocardial Infarction (STEMI).
What is the role of troponin in diagnosing myocardial infarction?
Troponin levels rise 4-8 hours after MI onset, peak at 18-24 hours, and remain elevated for up to 10 days, allowing late diagnosis and detecting re-infarctions.
Why do troponin levels rise?
Infarction to the myocardiocytes. Necrosis causes troponin to be released into the bloodstream.
What characterizes a STEMI?
A plaque rupture leading to thrombosis, causing irreversible necrosis of heart muscle due to a long interruption in blood supply.
What changes do you see on an ECG for a STEMI?
ST segment elevation.
What distinguishes a Non-STEMI?
Myocardial necrosis with risk of progression to a STEMI, but with blood flow still present. Treatment focuses on relieving ischemia and preventing further MI or death.
Partial occlusion.
What changes do you see on an ECG for NSTEMI?
ST segment drop.
What is subendocardial ischemia?
Myocardial damage which is often confined to the deep (subendocardial) layer of left ventricular muscle - only subendocardial is affected.
What happens to the wall when a coronary artery is occluded?
Entire wall thickness from endocardium to epicardium is affected.
What are the key medications used in cardiovascular disease?
Antiplatelets, anticoagulants, fibrinolytics, beta-blockers, ACE inhibitors, calcium channel blockers, statins, and others like nicorandil and ivabradine.
How do nitrates work in angina treatment?
They vasodilate arteries and veins, improving coronary blood flow, reducing myocardial workload, and decreasing oxygen demand.
What are the uses of nitrates?
They are used for prophylaxis of angina and acute heart failure.
What are the side effects of nitrates?
Headache,
Flushing,
Hypotension,
Syncope,
Facial flushing,
Postural hypotension
Who are contra-indicated from nitrates?
Acute circulatory failure,
Shock,
Head trauma,
Severe hypotension,
Aortic stenosis
Why is GTN used and how is it administrated?
Short acting
2 x sublingual and every 5 minutes
What is the action of beta-blockers?
They block beta-1 adrenoreceptors, reducing heart rate, force of contraction, and cardiac workload, which lowers myocardial oxygen demand.