Peer tutorial Flashcards
What are the two major patterns of MI?
- Transmural (usually STEMI)
2. Subendocardial (usually NSTEMI)
What conditions are characterised as acute coronary syndromes and which ones are characterised as chronic coronary syndrome?
ACS: 1. Unstable angina 2. Myocardial infarction 3. Sudden cardiac death CCS: 1. Stable angina 2. Chronic myocardial ischemia
Histological features 1 day post MI
Irreversible injury: Key: - Eosinophilic - Hemorrhagic, therefore RBCs Other: - Coagulative necrosis - Breakdown of nuclei - Disarray - Not many inflammatory cells
Histological features 3-7 days post MI
Acute inflammation:
- Neutrophils
Histological features 1-2 wks post MI
Early granulation tissue:
- Complete disarray
- Fibroblasts (main cell). These won’t appear earlier.
- Macrophages
- Capillaries
- Lymphocytes
Histological features 6-8 wks post MI
Scar tissue:
- No structure, just scar tissue
- Scattered fibroblasts
- Eosinophilic
Gross pathology of MI 3-10days post event
- Pale (coagulative necrosis)
- Thin (after some time)
- Fibrous
Supply of the LAD
- Anterior 2/3 of septum
- Anterior wall of LV
Supply of left circumflex
- Lateral wall of LV
Supply of right coronary artery
- SA/AV node
- Posterior 1/3 of septum
- Right ventricle
Complications of MI
Immediate: 1. Arrhythmias 2. Acute cardiac failure 3. Cardiogenic shock Days: 1. Mechanical complications (papillary muscle or wall rupture, acquired VSD) 2. Infarct expansion 3. Pericarditis 4. Arrhytmias 5. Mural thrombus formation 6. Progressive cardiac failure Weeks-months 1. LV aneurysm and thombus formation 2. Chronic cardiac failure - this is KEY 3. Arrhythmias (hear block, sick sinus syndrome)
Complications of MI
Immediate: 1. Arrhythmias 2. Acute cardiac failure 3. Cardiogenic shock Days: 1. Mechanical complications (papillary muscle or wall rupture, acquired VSD) 2. Infarct expansion 3. Pericarditis 4. Arrhythmias 5. Mural thrombus formation 6. Progressive cardiac failure Weeks-months 1. LV aneurysm and thombus formation 2. Chronic cardiac failure - this is KEY 3. Arrhythmias (hear block, sick sinus syndrome)
Complications of MI
Immediate: 1. Arrhythmias 2. Acute cardiac failure 3. Cardiogenic shock Days: 1. Mechanical complications (papillary muscle or wall rupture, acquired VSD). N.B. Ventricular septal defect. 2. Infarct expansion 3. Pericarditis 4. Arrhythmias 5. Mural thrombus formation 6. Progressive cardiac failure Weeks-months 1. LV aneurysm and thombus formation 2. Chronic cardiac failure - this is KEY 3. Arrhythmias (hear block, sick sinus syndrome) N.B. At all stages there is the possibility of arrhythmia and cardiac failure (acute -> progressive -> chronic)
Most common problem post MI
Chronic ischemic heart disease
Causes of sudden cardiac death
- Fatal tachyarrhythmia (often can be idiopathic). Can be the 1st manifestation of ischemic heart disease
- Acute MI
What is an aneurysm
- Bulge/dilation of lumen in blood vessel wall. Not dissection, because blood still contained in lumen
- Caused by weakening in MEDIA
What is an aneurysm
- Bulge/dilation of lumen in blood vessel wall. Not dissection, because blood still contained in lumen
2 types of true aneursym
- Saccular (one side)
2. Fusiform (both sides)
What is false aneurysm
Pocket of blood but not in lumen (in layers of vessel). This is different from dissection, because dissection is not just one pocket, it also tears through media and tracks up the vessel.
2 types of true aneursym
- Saccular (one side bulges)
2. Fusiform (both sides bulge)
Causes of aneurysms
Key: 1. Congenital e.g. Berry aneurysm 2. Atherosclerotic Others: 3. Inherited 4. Infectious
3 key examples of aneurysm:
- AAA (fusiform)
- Berry (saccular). Major cause of subarachnoid haemorrhage
- LV (complication of MI -> weakening of wall)
2 key causes of aortic dissection
- Connective tissue diseases (e.g. Marfan’s due to Fibrillin 1 defect)
- Hypertension (most COMMON)
Where do dissections often occur?
- Arch of aorta