Pathology of Myocardial Infarction and its pathology Flashcards
What is Glagovian Remodelling?
The maintenance of lumen size despite the formation of plaque in the blood vessel. The external elastic membrane enlarges without minimising the lumen. This is seen in mild and moderate coronary artery diseases.
What is a vulnerable plaque?
A plaque that has a thin fibrous cap over a lipid-rich necrotic core that is prone to rupture.
What are the criteria to diagnose Acute Coronary Syndrome?
- Raised level of troponin with :
- clinical symptoms
- new ECG changes
- Imaging evidence of an infarction : echo, cardiac MRI
Some other causes of raised Troponin?
- cardiac contusion
- drug : trastuzumab
- cardiomyopathy : amyloidosis, haemochromatosis
- Congestive Cardiac Failure
- Aortic dissection
- Myocarditis
- Renal failure
- Pulmonary Thromboembolism
What is the immediate management of ST elevated Myocardial Infarction?
- Morphine
- Antiemetic : ondasetron, domperidone, metoclopramide
- Oxygen
- Nitrates
- Aspirin : 300mg PO
- Clopidogrel : 600mg (PPCI) ; 300mg (thrombolytics); 75mg is more than 75 years old
- Unfractionated heparin : 5KU iv
and then REPERFUSION THERAPY
What are the reperfusion therapies available?
- Thrombolytics (tissue plasminogen activator: Alteplase, reteplase; streptokinase)
- Primary Percutaneous Coronary Intervention (within 120 minutes of diagnosis)
What are the cardiac biomarkers?
- Troponin : rises dramatically but stays for a few days
- CKMB : rises sharply then falls after day 2
What are the benefits of percutaneous coronary intervention?
- speeds up recovery
- prevents stroke
- prevents future angina
- reduces length of stay in hospital
- reduces the chance of future myocardial infarction
What is the management of NSTEMI?
Medical management:
- Aspirin
- Clopidogrel
- Statin
- Low Molecular Weight Heparin
- Beta blocker
- Tirofiban
Risk stratification using GRACE SCORE
What is the GRACE score for?
To evaluate the risk of NSTEMI patients that require urgent inpatient angiogram (if score is > 140).
What is the key difference between the management of STEMI and NSTEMI/ Unstable Angina?
STEMI : initial medical management (heparin + aspirin + clopidogrel + morphine + anti emetic) + REPERFUSION THERAPY (thrombolytics or PCI)
NSTEMI : Medical management (Aspirin, clopidogrel, statin, LMWH, Beta blocker) + if Grace score is >140 : urgent angiography to check the occluded vessels then maybe arrange for PCI
Complications of MI?
Arrhythmia, Heart failure, Cardiogenic shock, Rupture of myocardium, Pericarditis
