B.5 Myocardial Infarction Flashcards
Name two acute coronary syndromes
Unstable angina or acute MI
What biological event leads to myocardial infarction?
Thromboembolism or rupture of plaque
What are the symptoms of myocardial infarction?
symptoms :
Prolonged cardiac pain
- Chest, throat, arm epigastrium or back
breathlessness collapse anxiety nausea may be a silent MI
What are the signs of myocardial infection?
Pallor/sweating/tachycardia (due to sympathetic activation
vomiting/bradycardia
Signs of impaired cardiac function
Hypotension,oliguria,cold extremties
narrow pulse pressure
Lung crepitations
How would you diagnose a myocardial infarction?
ECG
S-T elevation is an early and common feature (STEMI)
Non-STEMI- unstable angina/partial thickness infarcts
cardiac enzymes Troponin T Creatine kinase (CK) Aspartate aminotransferase (AST) Lactate dehydrogenase (LDH)
What complications can myocardial infactions lead to?
Arrhythmias ventricular fibrillation Atrial fibrillation Heart block Ischemia Mechanical complications
What are the goals of treatment for myocardial infarctions?
Pain relief
Restore coronary flow/limit infarct size
Prevent/reduce arrhythmias
Prevent reinfarction
How does thrombolysis work?
Dissolves the clot, with reperfusion, salvage the cardiac muscle
Describe the pharmacology of how thrombolysis works
Drug thrombolytics activates plasminogen which then produces plasmin which dissolves fibrin in clots allowing the reperfusion of blood
What drug can be given to patients to reduce the chances of arrhythmias and improve survival after a heart attack?
Beta-blockers
What other benefits do beta-blockers have when given to patients who have suffered a myocardial infarction?
Improves myocardial perfusion
Reduces infarct size
Reduces chances of cardiac rupture
Can beta-blockers be used in patients who have bradycardia or heart failure?
No
Can beta-blockers be stopped abruptly after myocardial infarction and why?
No, if stopped, they increase the risk of a MI
If beta-blockers cannot be given to contraindicated patients, what would be an alternative, provided that the person doesn’t suffer from heart failure?
Calcium channel blocker, such as verapamil
What medicine should the patient be on after the discharge of a MI?
Aspirin and/or clopidogrel Beta-blocker (or ca-channel) ACEI Statins Depression medicines
