Myocardial Infarction Flashcards
What is a myocardial infarction?
A heart attack. It occurs when blood flow stops to part of the heart causing damage to the heart muscle.
What are the anatomical structures affected in an MI?
The left and right coronary arteries and their branches
What are the structural abnormalities during an MI?
- Narrowing of the arteries as a result of coronary atheroma
- Blockage of the arteries due to blood clot
What are the physiological abnormalities during an MI?
- Ischemia (an inadequate blood supply to an organ or part of the body) leading to necrosis of the heart muscles
- Impaired contraction of the myocardium
- Abnormal electrical activity of the heart cells
What causes a Myocardial Infarction?
- Family history of heart disease
- Smoking
- High BP
- High Cholesterol
- Diabetes (high blood sugar)
- Obesity
- Low exercise
What are the signs and symptoms of a Myocardial Infarction?
- Severe crushing chest pain
- Radiating pain spreading to arms (left specifically) and neck
- Associated nausea, vomiting, sweating and breathlessness
- Low BP
- Tachycardia
- Pulmonary Oedema
What are the abnormal test results associated with an MI?
- ECG showing ST segment elevation
- Blood tests showing raised levels of Troponin
- Echocardiogram showing reduced contraction
- Coronary angiogram showing artery blocked by atheromatous stenosis and by blood clot
What medical and surgical interventions are available?
- Pain relief with Morphine
- Administration of high flow oxygen
- Oral aspirin
- Primary percutaneous coronary intervention
What is primary percutaneous intervention?
This has replaced thrombolytic drugs. The clot is removed through a thin tube in the arm or leg and a small balloon is used to open the narrowed artery and a metal stent placed to hold the artery open.
What are the primary and secondary preventions of Myocardial Infarctions?
- Avoidance or treatment of risk factors
- Aspirin
- Clopidogrel
- Beta-blockers
- Statins
- Ace-inhibitors
