NSTEMI and Unstable Angina Flashcards
Define acute coronary syndrome
Term applied to patients in whom there is a suspicion of myocardial ischemia
What conditions are included in acute coronary syndrome?
- Unstable angina (UA)
- ST elevation MI (STEMI)
- Non-ST elevation MI (NSTEMI)
What is the pt care of someone with suspected ACS?
- Confirm Dx by ECG and biomarker measurement
- Relieve ischemic pain
- Assess hemodynamic state and correct abnormalities that may be present
- Initiate antithrombotic and re-perfusion therapy if indicated
Define MI
Clinical event caused by myocardial ischemia in which there is evidence of myocardial injury or necrosis
What are the criteria to diagnose an MI
- ↑ cardiac biomarkers + at least 1 of the following:
- Sx’s of ischemia
- New ST segment -T wave changes or new LBBB
- New pathologic Q waves
- Imaging evidence of new loss of viable myocardium or new regional wall motion abnormality
- Intracoronary thrombus by angiography or autopsy
What are the causes of MI?
- Usually result of thrombus formation on ruptured plaque
- Other causes include
A. Coronary artery vasospasm
B. Reduced myocardial blood flow
C. Excessive metabolic demand
D. Embolic occlusion
E. Vasculitis
F. Coronary artery dissection
G. Cocaine use
What are the sxs, prognosis, and complications of an MI dependent on?
Size and location of infarct
What do 20% of pts with an MI die from in the pre-hospital setting?
Usually from ventricular fibrillation
What percentage of MI’s are silent?
33%
What demographics have abnormal MI presentation?
Elderly
Women
Diabetics: due to nerve damage
What are the classic sxs of MI?
- Substernal CP or discomfort
- Radicular pain: pain between shoulder blades or that goes along a dermatome
- Dyspnea
- Nausea
- Diaphoresis
- +/-Syncope
Approximately 10% of pts have signs of heart failure w/ an MI. What are these signs?
- Pleural effusion
- Pulmonary edema
- S3 gallop
- Hepatic congestion: Hepato-jugular reflux
- Pedal edema
What are the diagnostic studies for a suspected MI?
- CK-MB
- Trop I and T
- Serum Myoglobin
- Serial EKGs
What is the timeline for CK-MB?
- Rises w/in 6 hrs, peaks @ 12-24 hrs, back to baseline 24-48 hrs post MI
- CK-MB is measured when a troponin assay is not available
What is the timeline for troponins?
- Trop T remains elevated longer than Trop I
- Troponin can rise 3 hrs post MI
- Trop I remains elevated for 7-10 days post MI
- Trop T remains elevated for 10-14 days post MI
What is the usefulness of serum myoglobin?
- Early indication of damage to myocardium
- More sensitive than CK-MB, but not as specific
- Trauma, inflammation and ischemic changes to noncardiac muscle will cause ↑ myoglobin levels