Acs Flashcards
What is acute coronary syndrome (ACS)?
A condition that develops when ischemia is prolonged and not immediately reversible, encompassing unstable angina, NSTEMI, and STEMI.
What are the two results of occlusion in acute coronary syndrome?
- Partial occlusion leads to unstable angina (UA) or NSTEMI
- Total occlusion leads to STEMI
What characterizes unstable angina (UA)?
- Change in usual pattern
- New in onset
- Occurs at rest
- Worsening pattern
- Unpredictable and a medical emergency
What is the result of sustained ischemia in myocardial infarction?
Irreversible myocardial cell death (necrosis) after more than 20 minutes of ischemia.
How long does it take for necrosis of the entire thickness of the myocardium to occur?
5–6 hours.
What area of the heart is most commonly involved in myocardial infarctions?
Most MIs involve some portion of the left ventricle.
What type of pain is associated with total occlusion in myocardial infarction?
Severe, immobilizing chest pain not relieved by rest, position change, or nitrate administration.
What are common descriptions of chest pain in myocardial infarction?
- Heaviness
- Constriction
- Tightness
- Burning
- Pressure
- Crushing
What sympathetic nervous system responses occur during myocardial infarction?
- Release of glycogen
- Diaphoresis
- Vasoconstriction of peripheral blood vessels
- Skin may appear ashen, clammy, and/or cool to touch
What cardiovascular changes occur during myocardial infarction?
- Initially increased HR and BP
- Then decreased BP due to reduced cardiac output
- Crackles
- Jugular venous distension
- Abnormal heart sounds (S3 or S4, new murmur)
What are common complications after a myocardial infarction?
- Dysrhythmias
- Heart failure
- Ventricular aneurysm
- Cardiogenic shock
- Pericarditis
What is the most common complication following myocardial infarction?
Dysrhythmias, present in 80% of MI clients.
What is the significance of pathological Q waves on an ECG?
Indicates that at least half the thickness of the heart wall is involved in infarction.
What diagnostic studies are used to assess unstable angina and myocardial infarction?
- Detailed health history and physical exam
- 12-lead ECG
- Serum cardiac markers
- Coronary angiography
- Exercise stress testing
- Echocardiogram
What is the treatment of choice for confirmed myocardial infarction?
Emergent PCI (percutaneous coronary intervention).