Acute Coronary Syndromes Flashcards
What are the coronary arteries of the heart?
Right coronary artery
Left anterior descending coronary artery
Circumflex coronary artery
Left main coronary artery
What is acute coronary syndrome?
New onset of a collection of syndrome relating to a problem with coronary arteries
Causes myocardial ischaemia and if this is prolonged then leads to myocardial infarction
Describe stable angina?
Caused by stable coronary lesion
Predictable symptoms due to narrowing - chest tightness/ discomfort
Symptoms are relieved at rest
Describe the presentation of acute coronary artery syndrome?
Unstable coronary lesion
Unpredictable
May occur at rest
Includes myocardial infarction and unstable angina
What is included in coronary artery syndromes?
Unstable angina
Non-ST elevation myocardial infarction
ST elevation myocardial infarction - complete blockage of the artery
Describe unstable angina in term of the atheroma?
Unstable plaque which is disrupted
This causes platelets aggregation as fat exposed to blood
How do you detect cell death?
Positive cardiac biomarker
And one of: symptoms of ischaemia, new ECG changes, coronary problem on angiogram on biopsy and any other test showing change in cardiac damage
What does troponin show?
Is used as a specific biomarker
Allows contraction and if in bloodstream shows insult to cardiac
What are some non-coronary causes for rise in troponin levels?
Arrhythmia - stress on heart
Pulmonary embolism - causes strain
Cardiac contusion
Sepsis
Anaemia
When is evidence of MI seen?
Mismatch between cardiac blood supply and demand
What is type 1 MI?
Associated with ischaemia and due to primary coronary event - plaque erosion, rupture, fissuring and dissection
What is type 2 MI?
Imbalance in supply and demand of oxygen. Result of ischaemia but not from thrombosis ex. endothelial dysfunction or fixed atheroma
What could the history be of a patient with acute coronary syndrome?
Ischaemic sounding chest pain
May radiate to neck or arm
More of a discomfort or tightening rather than pain
Can be associated with nausea, sweating and SOB
What are some factors that increase cardiac risk?
Male, Age, Known heart disease, High blood pressure, High cholesterol, Diabetes, Smoker and Family history
What would you look for in an examination?
Unwell is STEMI, or may be completely fine
Often no features to find
Check HR and BP in both arms
Listen for murmurs and crackles in chest
What are key investigations to carry out?
ECG and blood tests
What does complete coronary occlusion look like on an ECG?
ST elevation initially
Later on Q waves
What does partial coronary occlusion look like on an ECG?
ST depression - ischaemia
T wave inversion
May be normal
No Q waves
What will a posterior MI look like on an ECG?
Will be opposite changes in the leads opposite those looking at that area - depression is seen instead of elevation
Can be if LCx artery is completely blocked
What is the difference on investigations between unstable angina and NSTEMI?
NSTEMI will have elevated troponin levels and unstable angina will not
What is reperfusion therapy?
Opening of blocked artery to restore flow
Mechanical - primary PCI
Pharmacological - strong blood thinner
Explain PCI
Percutaneous Coronary Innervation - angioplasty and stenting
In cath lab with balloon and stents
Balloon compresses the plaque so stent can now be deployed
What is the pharmacological option for STEMI?
Thrombolysis - very strong blood thinning medication
Can be given quickly and if not able for surgery
What are the risks of thrombolysis?
Bleeding
So don’t give if recent stroke or previous intracranial bleed
Caution with recent surgery or sever hypertension
What is the options for a patient with STEMI who can get to lab in 2 hours?
Transfer to cath lab for primary PCI
If not then thrombolysis then transfer
What is the management for Unstable angina and NSTEMI?
Admit to hospital, ECG, Attach to cardiac monitor, Gain IV cannula access and give O2 only if levels low
What is the treatment for ischaemic pain?
Glycerol trinitrate (GTN)
Opiates if continue pain so need pain killer
Describe Glycerol trinitrate (GTN)
Vasodilator
Can give sublingual or IV
Wont help if artery is completely blocked
Describe what opiates do?
Ex. morphine
Helps relieve anxiety and is a painkiller
Helps vasodilate which may have haemodynamic benefits
What are some anti-platelets drugs given?
Aspirin
Plus one of these - Clopidogrel, Ticagrelor and Prasugrel
What are some anti-coagulant drugs given?
Prevent formation of fibrin
Heparin
Fondaparinux
Usually given as injection
Describe beta blockers
Reduce work of heart as reduce sympathetic drive
Beneficial acutely
Reduce long term CV risks
Describe statins
Stabilises plaque and works independent of cholesterol level
Cholesterol lowering drug
Describe an ACE inhibitor
Helps heart muscle recover and useful in loner term
Should patients with NSTEMI have a coronary angiogram?
If have high risk features then benefit from early invasive treatment
Most get angiogram unless likely to be type II MI
Ideally do angiogram in 48hours
What are the risk of PCI and coronary angiogram?
Bleeding from arterial site, MI, coronary perforation, emergency CABG, Stroke and the dye can affect function of kidneys
When dies a patient need a coronary artery bypass graft?
Three vessel disease
Left main stem disease
Disease not amendable to PCI
What is the management for ACS in hospital?
Keep attached to cardiac monitor for 24-48 hrs and listen for new murmurs or signs of heart failure
Start secondary prevention medications
Organise ECHO
Describe ventricular fibrillation?
Arises from ventricles - beats faster and out of rhythm
Patients unresponsive very quickly
What are some mechanical complication from post-MI?
Myocardial rupture
Acute ventricular septic defect
Mitral valve dysfunction
Describe a myocardial rupture
Damage to myocardial wall and causes blood to get into pericardium causing tamponade
Fatal unless detected and drained
Describe acute ventricular septal defect?
Damage to muscle - LV and RV
Flow from LV to RV and patient is very unwell
