Presentation And Tx Of Acute MI Flashcards
Morphine
Used to control pain associated with acute MI
- reduces afterload and preload
- reducing the preload may improve angina symptoms and chest pain
- controversial useage since some studies show increased mortality
- primarily used in the setting of angina and MI, is controversial in the use of Heart block and hypotension due to decreasing blood pressure*
- however for testing and boards purposes, use morphine for these incidents
Treatment of STEMIs
Need treatment before 3hrs
- 50% reduction in mortality if treated before 3 hrs
- can treat up to 12 hrs after onset of symptoms
Goal of treatment is to limit infarct size and preserve left ventricular function
Treatment options =
1) fibrinolysis ( only serious incidents)
- requires door-needle time less than 30 min
- includes tenecteplase or reteplase w/ coadministration of HMW heparin or P2Y12 inhibitors
2) percutaneous coronary interventions (STENTS Or valvular angioplasty)
- this is preferred option unless it cant be done
Contraindications of fibrinolysis drugs (tPA)
History of brain hemorrhages
History of strokes less than 3 months ago
Aortic dissection is likely
Active bleeding currently
Severe uncontrolled hypertension (>180/>110)
- must fix first, then treat
Significant head trauma
Indications for fibrinolytic therapy
1) Onset of STEMI within 12 hrs without contraindications
- most effective within 90 min of symptoms
2) new LBBBs
PCI
Includes angioplasty, valvuloplasty and stenting
- often used in acute coronary syndromes over tPA (unless PCI cannot be done within 90 minutes) since it has low contraindications
- must use in cardiogenic shock
also requires duel anti-platlet therapy for 12 months (asprin and P2Y12 inhibitor)
When to choose PCI over Fibrinolytics?
When in doubt use PCI over fibrinolytics as long as its possible
only time for fibrinolytics is when PCI is not possible within 90 min.
- possess higher mortality so is less safe
What rhythm is most common in ECGs after reperfusion?
Accelerated idioventricular rhythm
- this is usually limited and is more of a good sign that treatment worked
- DONT treat, just let it resolve
What types of MIs can result in AV blocks?
1) Inferior MI w/or without posterior MI
- blockage of the RCA blocks blood flow to the SA/AV nodes
2) anterior MI
- more dangerous than inferior MI blockage
consider using atropine, however may not respond
What type of MI results in LBBB sometimes?
Anterior MI
If MI + new LBBB = treatment for acute MI (lidocaine primarily)
Pericarditis
Visceral/parietal layers have infection/inflammation
- pain decreases w/ sitting up
Is called Dressler syndrome if it occurs after post MIs
- generates pericarditis and/or pleural effusions via inflammation or immune related interactions
Ventricular aneurysm on an ECG
Persistent ST elevation in the anterior leads often present w/ Q WAVES (PAST MI)
Usually caused by mural thrombosis so treatment consists of anticoagulants to break up the thrombosis
Treatment for right ventricular infarct
Blood supply occluded = RCA (85%), left circumflex (15%)
Presents with distended neck veins, clear lungs and hypotension
ECG abnormalities = ST elevation in V1-2 ; ST elevation greater in lead 3 than lead 2
To:
- PCI if severe (shows signs of heart failure)
- IV bolus of lidocaine, BBs or CBBs, fluid overload overtime
DONT use nitrates or morphine (since these increase preload to a failing right ventricle)
Tx for post myocardial infarction
Usually Lifelong aspirin and/or P2Y12 (“Grel”)
- If stent placed, must use for 1 yr regardless
BBs are required to be started within 24 hrs after unless contraindications
- often used for life as well
Lifelong statins
Why is nitroglycerin used for burning/pain in the chest
Nitrates decrease myocardial preload as their primary effect
- do this by increasing venous capacitance and induce venous pooling
Most pain/burning is caused by increased preload/ oxygen demand is higher than cardiac supply
CONTRAINDICATED in right ventricular infracts
Leads that show ST elevation for a septal/anterior MI?
V1-4 will show ST elevation
- Left anterior descending artery is occluded
- just need 2 leads*