Week 3 - Acute Coronary Syndrome/MI Flashcards
what is acute coronary syndrome
- when myocardial ischemia is prolonged and not immediately reversible
- umbrella term for situations where the blood supplied to the heart muscle is suddenly blocked or reduced
acute coronary syndrome encompasses the spectrum of… (3)
- unstable angina
- non ST segment elevation MI
- ST segment elevation MI
each remains a seperate diagnosis, but ACS reflects the relationship among them
ACS is associated w…
- an atherosclerotic plaque that was once stable
- plaque ruptures = stimulates platelet aggregation & local vasoconstriction w thrombus formation
= either partial occlusion by a thrombus or total occlusion by a thombus
what does partial occlusion by a thrombus manifest as
- unstable angina
- NSTEMI
what does total occlusion by a thrombus manifest as
- STEMI
what is unstable angina
- chest pain that is new in onset, occurs at rest, or has a worsening pattern
what is the difference between unstable agina & chronic stable angina
UA =
- unpredictable
- progresses rapidly in past few hours, days, or weeks
- more frequent
- easily provoked by minimal or not exertion (even at rest or sleep)
- medical emergency
what are prodormal symptoms of UA (4)
- fatigue
- SOB
- indigestion
- anxiety
what diagnostic tests are used for UA (2)
- EKG
- bloodwork (serum cardiac markers) 4-8 hx2 after a MI
what are 3 types of serum cardiac markers
- troponin
- CK-MB
- myoglobin
what is the difference between a NSTEMI and STEMI
- STEMI = classic heart attack, extensive cardiac damage, infarction, injury to heart
- NSTEMI = ischemia
what causes a MI
- occurs as a result of sustained ischemia, causing irreversible myocardial cell death
what do most MIs occur d/t
- thrombus formation
what does a thrombus in the myocardium result in
= perfusion to the myocardium distal to the thrombus stops = necrosis = contractile fnxn of heart in that area stops
the degree of altered fnxn in MI depends on
- area of heart involved and size of infarction
how long can cardiac cells withstand ischemic conditions before dying? how long until full thickness death
- 20 min
- full thickness death = 5-6 hr
= time matters!
location of infarction depends on
- the involved coronary circulatio
the description of an infarction depends on
- location of damage
ex. anterior, inferior, lateral, etc. - often involves left vent.*
what kind of pain is associated w MI
- severe, immobolizing chest pain not relieved by rest, position change, or nitrate admin
how is pain in MI described (7)
- heavy
- pressure
- tightness
- burning
- constriction
- crushing sensation
- more severe than usual anginal pain
what are common location of pain during an MI (7)
- retrosternal
- substernal
- epigastric
- neck
- jaw
- arms
- back
when does pain during an MI occur (3)
- while active or at rest
- asleep or awake
- common in morning hours
how long does pain during an MI last
- 20 min or more
what are some non-classic signs of an MI (4)
- discomfort
- weakness
- SOB
- fatigue
patients w DM are more likely to…
- experience silent MIs d/t cardiac neuropathy
older adults experiencing an MI may have what symptoms? (5)
- change in mental status (confusion)
- SOB
- pulmonary edema
- dizziness
- arhythmias
why do you experience SNS stimulation during an MI
- during initial phase, catecholamines are released from the ischemic myocardial cells
what signs of SNS stimulation are seen during an MI (4)
- release of glycogen
- diaphoresis
- vasoconstriction of peripheral blood vessels
- ashen, clammy, cool skin
what cardio & resp signs are seen during an MI (7)
- initially: HR & BP increase
- later, BP drops d/t decreased CO
- crackles in lungs (= left vent dysfunction)
- jugular venous distension
- hepatic enlargement
- peripheral edema (this + 3 above indicate right vent dysfnxn)
- abnormal heart sounds
what does the drop in BP later in an MI cause
- decreased renal perfusion & urine output
why does NV occur during MI (2)
- d/t reflex stimulation of vomitting centre by severe pain
- vasovagal reflexes initiated from the area of infarction
describe fever during MI (2)
- may rise during first 24 h
- may last as long as 1 week
why does fever occur during MI
- systemic manifestation of the inflammatory process caused by myocardial cell death
what are complications of a MI (7)
- dysrhythmias
- HF
- cardiogenic shock
- papillary muscle dysfunction
- ventricular aneurysm
- pericarditis
- dressler’s syndrome
how can dysrhythmias occur in MI
- dysrhythmia is caused by any condition that affects the myocardial cell’s sensitivity to nerve impulses –> ex. ischemia
how can MI cause HF
- if enough tissue has died that the pumping power of the heart has diminished
what is cardiogenic shock
- condition in which inadequate O2 and nutrients are supplied to the tissues d/t severe left ventricular failure
- body suddenly cannot pump enough blood to meet body’s needs
how does MI cause papillary muscle dysfnxn
- occurs if infarcted area includes or is adjacent to the papillary muscle that attaches to the mitral valve
what does papillary muscle dysfnxn cause
- mitral valve regurgitation = backflow of blood = increased vol of blood in left atrium
how can a MI lead to ventricular aneurysm
- if the infarcted myocardial wall becomes thinned and bulges out during contraction
what is used to diagnose UA/MI (5)
- history
- physical exam
- ECG
- measurement of serum cardiac markers
- coronary angiography
what should you look at in an EKG for MI
- QRS complex
- ST segment
- T wave
what are serum cardiac markers
- proteins released into the blood in large quantities from the heart muscle after a MI
what do serum cardiac markers indicate
- whether cardiac damage is present
- approx extent of damage
list 3 cardiac markers; which two are usually used to diagnose MI
- troponin and creatine kinase usually used
- myoglobin
what is the pro and con of CK levels
-
what is the pro of using troponin lvls
- myocardial specific
- goes up 3-12 hour post MI
- peaks at 24 hr
- goes back to baseline after 5-14 days
what is the pro and con of myoglovin (3)
- one of the first serum cardiac markers to increase after MI
- not cardiac specific
- rapidly excreted in urine = back to normal range in 24 hr after an MI
what is the pro to CK
- don’t return to normal for 2-3 days
what is a coronary angiography
- procedure that uses a special dye (contrast material) and x-rays to see how blood flows through the arteries in your heart.
- determine if any blockage in coronary arteries
why is a coronary angiography used as a diagnostic for MI
- evaluate extent of disease
- determine most approp treatment
what is imp in treatment of ACS
- rapid diagnosis & treatment to preserve cardiac muscle
what initial management is completed for ACS (12)
- ensure patent airway
- O2 (2-4L)
- continuous ECG (12-lead)
- establish IV route (2 IVs)
- assess pain
- give meds for pain
- vitals & O2 sats
- obtain baseline blood test results (cardiac monitors)
- bed rest & limitation for 12-24 hr, w gradual increase
- percutaneous coronary intervention
- reperfusion therapy
- admin antidysrhythmic therapy if needed
why is it important to establish an IV in inital treatment of ACS
- for emergency drug therapy
what meds are given in treatment of ACS (3)
- sublingual nitro
- aspirin
- Iv morphine ( for pain unrelieved by nitro)
what is done if dysrhythmias are detected during ECG monitoring
- appropriate treatment administered
when specifically should VS and O2 sats be monitored
- monitor frequently during first few hrs of admission
- closely after
what does reperfusion therapy do
- opens coronary artery that was occluded
= restored blood flow to the heart & saved heart muscle
when is PCI considered for treatment of ACS
- when pt is stabilized and angina is controlled
- or if angina returns & increases in severity
what are types of reperfusion therapy done for treatment of ACS (5)
- emergent percutaneous intervention
- fibrinolytic therapy
- meds/drug therapy
- CABG
- minimally invasive direct coronary artery bypass
what is percutaneous coronary intervention
- intervention to treat CAD in which a catheter equipped with an inflatable balloon is inserted into a narrowed coronary artery & the balloon is inflated
where can an emergency PCI be performed
- in facilities w an interventional cardiac catheterization lab
what type of ongoing monitoring should occur in treatment of ACS/MI (7)
- VS + O2 sats
- LOC
- cardiac rhythmn
- monitor response to meds (pain) & readminister if needed
- provide reassurance and support to pt and family
- anticipate need for intubation if respiratory distress is evident
- prep for CPR, defib, cardioversion
what is the goal of emergency PCI
- open the affected artery within 90 min of pt’s arrival to ED
- urgent!
what occurs in EPCI
- pt undergoes cardiac catheterization to locate blockage, assess severity, etc.
what are benefits of EPCI (5)
- alternative to surgery
- uses local anasthetic
- pt ambulatory 24 hr after procedure
- length of hospital stay 1-3 days = lower hospital costs
- pt can make rapid return to work (5-7 days)
what is the goal of fibrinolytic therapy
- stopping the infarction process by dissolving the thrombus in the coronary artery and reperfusing the myocardium
when should fibrinolytics be given
- within 30 min to 1st hour = ideal
- within first 6 hours = preferred
how are fibrinolytics administered
- IV
what is a risk associated w fibrinolytics
- may lyse other clots (ex. a postop site)
what are absolute contraindications for fibrinolytics (8)
- active internal bleeding or bleeding diathesis
- Hx of cerebral aneurysm
- arteriovenous malformation
- intracranial neoplasms
- previous cerebral hemorrhage
- ischemic stroke past 3 mo.
- signif close head or facial trauma within past 3 mo
- aortic dissection
what are relative contraindications for fibrinolytics (7)
- active peptic ulcer disease
- use of anticoags
- prior ischemic stroke not within 3 mo
- surgery or puncture of noncompressable vessel within past 3 week
- serious systemic disease
- severe uncontrolled HTN
- traumatic or prolonged cardiopulmonary resus (>10 min)
what must be done before fibrinolytic therapy (3)
- basline lab studies collected
- 2-3 lines for IV therapy started
- invasive procedures performed before
= reduced risk of bleeding
how long is fibrinolytic therapy give
- depends on drug selected
- either in 1 IV bolus or over time (30-90 min)
what should be monitored frequently during fibrinolytic therapy (3)
- VS
- O2 sat
- heart & lung assessments
what is a major concern w fibrinolytic therapy? what is done to avoid this
- reocclusion of the artery
- site of thrombus is unstable = another clot may form or spasm of the artery may occur
- may start on IV heparin to prevent
what is the major complication of fibrinolytic therapy
- bleeding = assessment is important!
what should nurses monitor for d/t the complication of bleeding in fibrinolytic therapy
- drop in BP
- increase HR
- decreased LOC
- blood in urine or stool
= bad
what is to be expected after fibrinolytic therapy
- minor bleeding
ex. surface bleeding at IV sites, gingival bleeding - control by applying pressure or ice pack
what are the meds of choice for ACS (10)
- IV nitro
- aspirin
- beta blockers
- systemic anticoag
- IV antiplatlets
- ACE-I
- calcium channel blockers
- antidysrhtymias
- cholestrol lowering drugs
- stool softeners
what med is used in initial treatment of ACS
- IV nitro
what effect does IV nitro have
- immediate onset of action
- decrease preload
- decrease afterload
= increased myocardial supply
what should be monitored when giving IV nitor
- BP
when is morphine sulfate given in tx of ACS
- for pain unrelieved by nitro
what effect does morphine have in tx of ACS
- vasodilator
- lowers myocardial O2 consumption
- reduced contractility
- decreases BP and HR
what is a s/e of morphine
- resp depression –> monitor for signs of bradypnea or hypoxia
who should IV beta blockers not be given to ? when should oral beta blockers be initiated for w STEMI
- pts w STEMI
- initiate in first 24 hr (if no contra)
what effect do beta blockers have in tx of ACS (4)
- reduce HR
- reduce BP
- reduce contractility
= decreased O2 demand
what is the most common complication aftee MI
- dysrhythmias
why are stool softeners given after MI
- pt is predisposed to constipation d/t bed rest and opioid admin
- prevents straining and vagal stim (which causes bradycardia and dysrhytmia)
what is a type of stool softener given after MI
- docusate sodium (colace)
describe nutritional therapy for a pt with MI (5)
- initally: NPO except sips of water until stable
- advance as tolerated
- low salt
- low cholestrol
- low sat fats
when is CABG recommended? (4)
- no satisfactory improvement w medical management
- left main coronary artery or 3 vessel disease
- not candidates for PCI (lesions long & difficult to access)
- if PCI has failed & chest pain is ongoing
what is coronary artery bypass graft surgery
- construction (grafting) of new vessels between the aorta, other major arteries, and the myocardium distal to the obstructure coronary artery
what does CABG surgery require
- sternotomy = opening of chest cavity
- cardiopulmonary bypass CPB
what is CPB
- involves diverting the pt’s blood from the heart to the CPB machine
- blood is oxygenated in the blood and then returned via a pump to the pt
= vital organs perfsued while the surgeon operates on a nonbeating, blood-less heart
what is minimally invasive direct coronary artery bypass
- technique that offers the pt with single-vessel disease, an approach to surgical tx that does not involve a sternotomy and CPB
- involves several small incisions between the ribs & thorascope is used to dissect the IMA
how is the heart slowed during a MICABG
- by a beta blocker or stopped with adenosine
what type of dysarhythmia most often occurs within the 1st four hours of chest pain during an MI
- ventricular fibrillation
what factors can precipitate angina (8)
- physcial exertion
- temp extremes
- strong emotions
- consumption of a heavy meal
- tobacco use
- sexual activity
- stimulants
- circadian rhythm patterns
what are priority nursing interventions during the initial phase of ACS
- pain assessment and relief
- physiological monitoring
- prompt rest & comfort
- alleviate stress & anxiety
- understand pt’s emotional and behavioral rxns
what can be given for pain associated w ACS (3)
- nitro
- morphine
- O2
= all decrease chest pain
what physiological monitoring should be done with ACS (6)
- continuous ECG monitoring
- VS
- intake & output
- physical assessment for variations from baseline
- lung & heart assessment
- o2 status
what comfort measures can promote rest in a pt (6)
- frequent oral care
- adequate warmth
- quiet atmosphere
- use of relaxation therapy
- assurance that personnel are nearby and responsive to their needs
- bed rest
what are the major nursing responsibilities for a pt after a PCI
- signs of recurrent angina
- assess VS (including HR and rhythm)
- signs of bleeding
- maintenance of bed rest
most of the complications after CABG are related to??
- use of CPB
what are major consequences of CPB (3)
- bleeding and anemia (d/t damage to RBC)
- fluid and electrolyte imbalances
- hypothermia (bc blood is cooled as passes thru)
nursing care post-CABG focuses on (9)
- monitor hemodynamic status
- monitor fluid status
- assess for bleeding
- electrolyte replacement
- restore temp
- post-op dysrhythmias (first 3 days after esp.)
- surgical site care
- prevent infection
- pain mngmt
why is exercise an important aspect of the rehab program for ACS (8)
- increases CO
- decreases blood lipids
- decreases BP
- increases blood flow thru coronary arteries
- increase msucle mass
- improve psychological state
- assist in weight loss
- maximal o2 uptake
what should be taught regarding physical activity for a pt with ACS (4)
- regular schedule of physical activity
- “listen to what ur body is saying” –> dont overexert
- check the pulse rate while exercising –> give pt max HR
& if they exceed this or does not return to resting pulse in a few min, they should stop and rest - stop exercising if angina occurs
what are the most common arteries involved in an MI
- left circumflex
- left marginal
- left anterior descending
what is the most dangerous blockage in an MI
- left coronary artery bc it impacts many branches
what is the downside to PCI
- high risk within 30 days of causing vascular spasm or failing to hold back plaque = risk of repeating MI
