ACS Flashcards
(45 cards)
What are the three major acute coronary syndromes (ACSs)?
- Unstable angina
- Non–ST segment elevation MI (NSTEMI)
- ST segment elevation MI (STEMI)
These are critical classifications used in diagnosing and managing acute coronary events.
What occurs when the ischemic process is not interrupted?
Infarction occurs, resulting in tissue death.
This highlights the importance of timely intervention in acute coronary syndromes.
Why is early recognition of ACS critical?
It limits the loss of heart tissue.
Prompt diagnosis and treatment can significantly affect patient outcomes.
What does ischemia indicate on an ECG?
ST-segment depression.
This can be a key indicator of unstable angina or NSTEMI.
What does myocardial injury indicate on an ECG?
ST-segment elevation.
This is a critical sign in diagnosing STEMI.
What may or may not be demonstrated by the appearance of pathologic Q waves?
Infarction.
Pathologic Q waves can indicate a previous myocardial infarction but are not always present.
What does ST-segment depression greater than 0.5 mm in 2 or more contiguous leads indicate?
Unstable angina or NSTEMI.
This is an important diagnostic criterion in the assessment of chest pain.
When should STEMI be suspected based on ST-segment elevation?
If ST-segment elevation is:
* 2 mm or more in men older than 40 years
* 1.5 mm or more in women
* 1 mm or more in the other leads
These thresholds are critical for timely intervention.
What is referred to as a nondiagnostic ECG?
An absence of ST segment changes associated with an ACS presentation.
This indicates that the ECG did not provide clear evidence of ACS.
When should the first 12-lead ECG be obtained?
Within 10 minutes of patient contact.
Rapid ECG acquisition is essential for the timely diagnosis of acute coronary syndromes.
What is the usual cause of an ACS?
The rupture of an atherosclerotic plaque
How does atherosclerosis affect blood vessels?
It narrows the vessels and reduces the flow of blood through them
When does the atherosclerotic process begin?
In childhood
What is deposited along the inner wall (intima) of arteries during atherosclerosis?
Small amounts of fatty material
Where does the deposition of fatty material usually occur?
At points of turbulent blood flow, such as where arteries branch or where the arterial wall is damaged
What does the streak of fat gradually enlarge into?
A mass of fatty tissue called an atheroma or atheromatous plaque
What happens to an atheroma over time?
It calcifies, hardening into a lesion that infiltrates the arterial wall
What effect does the expanding atheroma have on the artery?
It narrows the artery, decreasing the blood flow through the lumen
What is an ideal site for the formation of a thrombus?
The narrowed, roughened area of the arterial intima
What is the term for a clot that forms in a coronary artery?
Coronary thrombosis
What can calcium precipitate from the bloodstream cause?
Arteriosclerosis
What triggers a surge of catecholamines during the stress response?
Epinephrine and norepinephrine from the adrenal glands
What state does the peripheral circulation enter during the fight-or-flight response?
Severe vasoconstriction
What can lead to dysrhythmias and death in the heart?
Increased need for oxygen during oxygen deprivation
