Management of STEMIs-MJ Flashcards
How many minutes can a client experience cardiac ischemia before cell death occurs?
20 minutes, if longer than 20 minutes, myocyte injury is irreversible
What does myocardial injury trigger?
Ventricular remodling
What is ventricular remodeling?
A process when ventricular mass increases and the chambers change in volume and shape
What is ventricular remodeling driven by?
Local production of angiotensin II
What does ventricular remodeling increase the risk of?
HF and death
There are 4 main signs and symptoms for an acute STEMI. What are they?
- Presence of chest pain
- Characteristic ECG changes
- Elevated serum levels of myocardial cellular components
- “Other”
S&S for acute STEMI: Presence of chest pain
- Severe substernal pressure results in unbearable ____ or ______.
- Where does the pain radiate?
- How is this different from angina pectoris?
- unbearable crushing or constriction
- radiates down the arm and up to the jaw
- Pain by STEMI lasts longer! & not relieved by nitroglycerine
S&S for acute STEMI: Characteristic ECG changes
-What do we see almost immediately in response to ischemia: ST elevation or depression? Then what develops?
ST elevation..then a prominent Q wave develops in the majority of patients
*Q waves are small or absent in a normal ECG
S&S for acute STEMI: Elevated serum levels of myocardial cellular components
-What levels are looked at?
Troponin and creatinine kinase
S&S for acute STEMI: What are the 4 “other” symptoms?
Sweating
- Weakness
- Sense of impending doom
- Know that about 20% of people with STEMI experience NO symptoms
What are considered the BEST serum markers for STEMI?
Troponin!–cardiac troponin I and cardiac troponin T
Under normal conditions, troponin is NOT detectable in the blood. When do they come detectable?
2-4 hours after symptom onset and peaks 10-24 hours…they return undetectable again in 5-14 days.
What happens to troponin when STEMI occurs?
100 fold or more above the lower limits of detection
Measurements of troponin I and T are more -____ (sensitive or specific)
Sensitive
Before troponins, the preferred biomarker for STEMIs were measuring the creatinine-kinase (CK-MB). Where is CK-MB found?
Primarily in cardiac muscle rather than skeletal muscle
What does an increase in serum CK-MB mean?
Cardiac injury
What medication must be given immediately to a client with a STEMI? What meds should be discontinued?
Aspirin can be given..all other NSAIDs should be discontinued!!!!
NSAIDs, with the exception of aspirin, have a BBW for increased risk of stroke and MI
Why do we give aspirin immediately to a client with a STEMI?
Suppresses platelet aggregation (producing an immediate anti-thrombiotic effect)
When should aspirin therapy begin and when should it end?
Aspirin therapy should begin immediately after onset of symptoms for a STEMI and it should be continued indefinitely!
Why is chewable aspirin given for the first dose?
The first dose should be chewed to allow rapid absorption across the buccal mucosa
What should the dose be for the chewable aspirin?
162-325 mg
For prolonged aspirin therapy, what should the dose be? And why do we give aspirin indefinitely after STEMIs?
81-162 mg/d
Reduces the risk of re-infarction, stroke, and death
What is the analgesic of choice for STEMIs?
IV morphine
What does IV morphine improve?
Hemodynamics and relieves pain
What does IV morphine reduce?
Cardiac PRELOAD by promoting venodilation
Since IV morphine reduces preload, that means it ____ the work of the heart
Decreases
IV morphine also may cause some reduction in after load by promoting _____
Arterial dilation
IV morphines combined reduction in preload and after-load _____ cardiac oxygen demand and that helps preserve the ischemic myocardium
Lowers
What BB reduces cardiac pain, infarction size, and short-term mortality?
Atenolol and metoprolol
Continued use of oral BB _____ long term survival
Increases
T/F: Nearly all patients can benefit from BB, but many don’t get them.
True
T/F: The patients that DO get a BB, get a dose that is too high.
False. The patients that do get the BB usually has a dose that is too LOW
As STEMI evolves, the HR and force of contraction rises substantially, _____ cardiac demand.
Increases
