Anatomy and Physiology Review
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Coronary arteries
Chambers of the heart
Perfusion
Pathophysiology: Acute Coronary Syndrome
- Atherosclerosis: The buildup of plaque (cholesterol, collagen, etc.) in between the layers of the arteries.
- Vessels narrow due to plaque buildup and subsequent decrease in blood flow
- Plaque rupture occurs, leading to localized clotting (thrombus)
- Vessel becomes occluded by thrombus, leading to disruption of oxygenated blood delivery to cells downstream (myocardial infarction)
Signs and Symptoms
- Discomfort in chest, jaw, neck, shoulders, arms and upper abdomen
- Shortness of breath (dyspnea)
- Nausea/vomiting
- Syncope
- Diaphoresis
- Cardiac arrest
Treatment: Acute Coronary Syndrome
- Initiate transport/request ALS.
- Consider appropriate destination hospital and make early notifications.
- If indicated, administer oxygen to maintain saturations of 94%.
- If permitted, obtain a 12-lead ECG.
- If no contraindications, administer 324 mg aspirin by mouth.
- If no contraindications, administer 0.4 mg sublingual nitroglycerin.
- May repeat after 5 min if no contraindications.
Important Concepts: Acute Coronary Syndrome
- Atypical is typical. Acute myocardial infarction has a wide range of presentations. Have a high degree of suspicion with any patient who has any combination of symptoms, and beware atypical presentations.
- Time is muscle. Intervention is time-sensitive. Delay means increased tissue damage and higher mortality rates.
- If allowed by protocol, use 12-lead ECG to confirm the diagnosis. However, remember that ACS cannot be ruled out with the absence of ECG findings.
- Consider cardiac arrest as a sign of ACS. Post-arrest patients should be treated for ACS because it is the most common cause.