Acute Coronary syndromes Flashcards
How is it defined?
Partially or totally occluded coronary artery which leads to myocardial ischaemia.
Different types of A.C.S.
- unstable angina
- STEMI
- NSTEMI
Defining characters of a STEMI?
- ST elevation
- Q waves
- hyper-acute T waves
- full myocardial cell thickness damage
- transmural MI
- complete occlusion of Coronary artery
Defining characters of an NSTEMI?
- no ST elevation
- Q wave NSTEMI or nQ wave NSTEMI
- ST depression/ T wave inversion
- Sub-endocardium MI
- Partial thickness damage
- partial occlusion of coronary artery
Diagnosis of an A.C.S.
- Chest pain: if it lasts more than 20 mins it is an A.C.S.
- ECG: ST elevation indicates STEMI
- troponin level increase indicates NSTEMI
- if no increase in troponin level- unstable angina
What could an increase in troponin also be a sign of
Pulmonary embolism
sepsis
renal failure
sub-arachnoid haemmorage
Classification of an MI
TYPE 1: sudden MI related to primary coronary artery event e.g. rupture TYPE 2: 02 demand mismatch Due to ischaemia but not C.A. event TYPE 3: Sudden cardiac death related to thrombus confirmed but after death TYPE 4: related to PCI or angioplasty TYPE 5: related to CABG
Aetiology of A.C.S.
- coronary artery atherosclerosis
- coronary artery inflammation
- vasospasm; cocaine, chemotherapy
- radiotherapy can cause fibrosis/stenosis
- embolism/thrombus down C.A.
Different types of M.I. and what vessels are they related?
inferior: R.C.A
anterior: left anterior descending
lateral : circumflex
posterior:
-difficult to detect because no posterior leads
-usually related to R.C.A.
-will show opposite events on ECG in opposite areas e.g. V1-V2
Symptoms
CHEST PAIN:
- lasting more than 20 minutes at rest
- retro-sternal
- radiating up jaw, neck, left arm
In diabetics, elderly, reduced sensitivity to pain:
- SOB
- nausea
- Syncope
- Sweatiness
When does it cause major damage?
-when proximal to the heart or when it affects a vessel which supplies major area of the heart
Sudden cardiac death:
- what are the causes
- stats
- When myocardial ischaemia lasts long enough to cause ventricular fibrillation
- Only 2% of patients survive
meaning of
- transmural
- subendocardium
Transmural: ischaemic necrosis which affects the whole heart
Subendocardium: Ischaemic necrosis which only affects part of the heart muscle wall
What is the reparative process for an M.I.
- cell death
- acute inflammation
- phagocytosis of dead cells
- granulation tissue formed
- collagen deposited
- scar formation
Most common complication within the first 24 hours of an MI?
Arrhythmia
