Acute coronary syndromes Flashcards
What is acute coronary syndrome?
A constellation of symptoms and clinical findings which result from impaired cardiac perfusion at rest.
Aetiology of acute coronary syndrome?
Usually due to a thrombus from an atherosclerotic plaque blocking a coronary artery.
Pathophysiology of acute coronary syndrome?
Most common cause is rupture or erosion of the fibrous cap of a coronary artery plaque
This leads to platelet aggregation and adhesion, localised thrombosis, vasoconstriction and distal thrombus embolisation.
What are the subtypes of ACS?
Unstable angina: subtotal occlusion, supply led ischaemia without infarction
NSTEMI: subtotal occlusion
STEMI: complete occlusion
What are the typical symptoms for chest pain in ACS (SOCRATES)?
- Site - central/left sided
- Onset - often sudden
- Character - crushing (‘like someone is sitting on your chest’)
- Radiation - left arm, neck and jaw
- Associated symptoms - nausea, sweating, clamminess, shortness of breath, sometimes vomiting or syncope
- Timing - constant, 30 mins or longer
- Exacerbating/relieving factors - worsened by exercise/exertion and may be improved by GTN (but not completely relived or else angina)
- Severity - Often extremely severe
What is xanthelasma?
A sign of atherosclerosis - fatty deposits on certain areas i.e. eyelids.
Investigations for acute coronary syndrome?
ECG: most important investigation and should not be delayed for other investigations (e.g. bloods). This will determine the immediate course of action.
Bloods: troponin, renal function, blood glucose, lipid profile and FBC.
CXR: looking for pulmonary causes of chest pain or pulmonary oedema.
Diagnostic features of unstable angina?
Unstable angina: Cardiac chest pain + abnormal /normal ECG+ normal troponin.
NSTEMI: Cardiac chest pain + abnormal/normal ECG (but not ST elevation) + raised troponin.
STEMI: Cardiac chest pain + persistent ST elevation/New LBBB (there is no need for troponin in this case).
Diagnostic features of STEMI?
ST segment elevation >2mm in adjacent chest leads
ST segment elevation >1mm in adjacent limb leads.
Diagnostic features of NSTEMI?
Two of the following:
- Cardiac chest pain
- Newly abnormal ECG which is NOT ST-elevation.
- Raised troponin (with no other reasonable explanation).
Changes in leads V1-V4 indicate which artery and territory?
Anteroseptal territory in left anterior descending artery
Changes in leads II, III and avF indicate which artery and territory?
Inferior territory in right circumflex artery
Changes in leads I, avL +/- V5-V6 indicate which artery and territory?
Lateral territory in proximal LAD artery
Initial management of ACS (MMONAC)?
Morphine
Metoclopramide (an antiemetic)
Oxygen if sats <94%
Nitrates (GTN spray)
Aspirin 300mg
Clopidogrel 300mg
