Acute Coronary Syndrome Flashcards
Define Coronary Artery Disease/Acute Coronary Syndrome
An umbrella term that refers to ischemic symptoms resulting from acute coronary occlusion.
Includes:
STEMI
Non-ST-elevation acute coronary syndrome (NSTEACS)
- NSTEMI and Angina
Aborted MI
- Absence of any residual myocardial damage, usually due to early and effective reperfusion therapy
Define atherosclerosis
CAD is often caused by plaque rupture/clot formation on the coronary arteries.
Atherosclerosis is a progressive disease process –> thickening and hardening of the arterial wall due to accumulation of lipid laden macrophages –> development of plaque.
Both innate and adaptive immune responses are involved.
Outline the pathophysiology of atherosclerosis in Coronary Artery Disease
STAGE 1 - Endothelial injury
Inflammation of the vessel wall from chronic epithelial injury (smoking, HTN etc) allows LDL cholesterol to move below the endothelial surface.
STAGE 2 - Fatty streak
Oxidized LDL cause monocytes (leukocyte involved in adaptive immunity) to adhere to endothelial cells and migrate to the vessel wall.
Within the artery wall, some monocytes differentiate into macrophages (engulf and destroy pathogens) that unite with and internalize oxidized LDL cholesterol (FOAM CELLS). Accumulation of foam cells causes a lesion (fatty streak).
STAGE 3 - FIBROUS PLAQUE
Collagen covers the fatty streak forming a fibrous plaque. Vessel lumen narrows. Fatty streak produces more toxic o2 radicals causing progressive damage to the vessel wall.
STAGE 4 - Complicated lesion
Plaque ruptures –> thrombus forms.
Exposure of underlaying tissue causes platelet adhesion, initiates clotting cascade, rapid thrombus formation causes occlusion, ischemia and infarct.
Identify the modifiable and non- modifiable risk factors for CAD
Modifiable: Oral contraceptives Smoking Heavy alcohol consumption Hyperlipidaemia HTN Obesity/physical inactivity Psychosocial factors
Non-modifiable: Advanced age Male gender Indigenous race Genetic predisposition Women >55y.o T1DM
Discuss the pharmacological management of patients with chest pain and the nursing considerations for each
GTN S/L every 5 minutes for 3 doses
- unless inferior infarct as can drop BP
IV Morphine 2.5-5 every 5 minutes
- be conservative for elderly patients with cardiorespiratory compromise
IV Fentanyl
- morphine can slow absorption of some medications such as ticagrelor
Aspirin 300mg dissolved/chewed
Pt of higher risk
P2Y12 inhibitor - ticagrelor/clopidogrel
Beta blocker can decrease myocardial workload
-use in caution with inferior infarct
Antiemetic if required
If STEMI/NSTEMI:
?heparin/enoxaparin
Discuss the pathophysiology and diagnostic criteria for a STEMI and NSTEMI
NSTEMI - troponin rise in the absence of ST elevation
Thrombus has lodged into the coronary artery causing infarction to the myocardium directly beneath the endocardium but breaks up before complete distal necrosis occurs (subendocardial infarction).
STEMI:
Troponin rise with ST elevation in 2 or more related leads or new RBBB
Thrombus has lodged permanently into the coronary artery causing infarction throughout the myocardium, endocardium and pericardium (transmural infarction).
Discuss the ED management of a patient experiencing an AMI
DRSABCD ECG Path - 1-3hourly is appropriate Supplemental O2 if SpO2 <93% GTN 5/24 (except inferior)
If Sx unrelieved: IV GTN IV Morphine/Fentanyl Aspirin 300mg - antiplatelet Antiemetic
P2Y12 inhibitor - ticagrelor/clopidogrel
Anticoagulant - enoxaparin
Within 12 hours of STEMI Sx - emergency reperfusion therapy [PCI (percutaneous coronary intervention) or fibrinolytic therapy]
- PCI preferred to reduce mortality, recurrent MI or stroke
Patients with NSTEMI should have an angiogram with coronary revascularization (PCI/CABG)
What are contraindications to PCI (percutaneous coronary intervention)
Severe contrast allergy
Poor vascular access
What are contraindications to fibrinolytic therapy
BP >180/100 Recent trauma/surgery GIT bleed <2weeks ago stroke/TIA <12 months ago prior ICH Current anticoagulation or warfarin allergy
Name the different fibrinolytics
Tenectaplase
Reteplase
Alteplase
Streptokinase
Describe how to differentiate between cardiac and non-cardiac pain plus the rest of learning outcomes
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