Acute Coronary Syndromes Flashcards
(42 cards)
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
