Acute Coronary Syndrome Part 1 Flashcards
(67 cards)
1
Q
What is the difference between NSTEMI and STEMI
A
- stemi: there is completely occlusion of the artery
- nstemi: lumen is occluded only partly- there is still some coronary blood flow
2
Q
What is the difference between the thrombus is the NSTEMI and STEMI?
A
stemi: full blown coagulation pathway and see a lot of fibrin here
nstemi: mainly platelets in the thrombus
3
Q
______ is an enzyme that is released when there is myocardial necrosis
A
troponin
4
Q
Where is the worst place to have an occlusion in the heart? Why is this?
A
- left main coronary artery
- this is the worst place because there is a large amount of downstream blockage
5
Q
Describe a STEMI
A
- most severe type of ischema in the pathophysiologic continuum of the acute coronary artery syndrome
- caused by complete occlusion of a coronary artery by clot (rupture of atherosclerotic plaque)
- STEMI comprises approx. 25-40% of MI presentations
- in hospital mortality rates are 4.6% vs 2.2% for patients with STEMI and NTEMI, respectively
6
Q
What are the classic presenting symptoms of coronary artery syndrome?
A
- central chest paon (typically radiating to shoulder, down the left arm, to the back or the jaw); may be accompanied by SOB, n/v, diaphoresis
7
Q
What are the symptoms associated with silent type MIs?
A
- no chest pain or discomfort
- more often here they describe SOB, indigestion or diaphoresis, other sx like fatigue, faintness, dizziness, light-headedness, anxiety and palpitation
8
Q
What demographic groups are less likely to have classic symptom presentation?
A
- elderly, diabetic patients and women
9
Q
What are the major SIGNS of acute coronary syndrome?
A
- syncope
- bradycardia (inferior infarction), tachycardia (increased sympathetic activity, decreased cardiac output), other arrhythmias
- elevated or low BP
- diffuse rales, wheezing or respiratory distress usually indicate pulmonary oedema and CHF
- jugular venous distention indicates right atrial hypertension, usually from RV infarction or elevated LV filling pressure
10
Q
What are the 2 enzymes that are released into the circulation when cardiac cells are damaged?
A
- creatinine kinase
- troponins
11
Q
What can be expected from CK (creatinine kinase) levels after an MI?
A
- these should be detectable in the serum within 3-5 hours after an MI, peaks in 12-24 hours, stays elevated for 2-3 days
- this can be elevated in other non-ACS conditions (e.g. pericarditis, myocarditis, rhabdomyolysis, renal failure)
12
Q
What is the preferred biomarker for detecting an acute coronary syndrome?
A
- troponins
13
Q
What can be expected from troponin levels after a coronary artery syndrome?
A
- troponin T appears in serum within 4-12 hours after an MI onset peaks in 12-48 hours, and stays elevated for 7-10 days
14
Q
When should biomarker essays be done after an MI?
A
- should be done stat on presentation, then should be redone every 4-6 hours for the first 12-24 hours, then periodically
15
Q
What needs to be seen on lab tests for the diagnosis of a STEMI or an NSTEMI?
A
- at least 2 elevated CK-MB or 1 TnT exceeding the upper reference range is needed (usually 2 successive blood samples)
16
Q
What are the advantages of an ECG?
A
- get results immediately
- can be very indicative of if patient is having a STEMI or something else
- will give the location of the infarct
17
Q
What signs on an ECG can be indicative of a STEMI?
A
ST elevation
18
Q
What signs on an ECG can be indicative of a NSTEMI?
A
ST depression
T wave inversion
19
Q
What is the main initial management of acute coronary syndrome? (4 things)
A
- oxygen at 4 L/min by nasal prong to maintain O2 saturation >90% (preferably 95%)
- ASA 162-325 mg po chew/shallow (if not already given by EMS)
- Nitroglycerin SL or IV
- Morphine 2-5 mg IV q5-30 min prn (could use other analgesics such as fentanyl) -if pain not relieved by nitro
can be described as MONA
20
Q
What is the main priority in STEMI?
A
- priority is to quickly reestablish blood flow to the occluded artery as quickly as possible (need to enhance perfusion)
21
Q
What is the main priority in STEMI?
A
- priority is to quickly reestablish blood flow to the occluded artery as quickly as possible (need to enhance perfusion)
22
Q
What are the 2 types of reperfusion strategies in STEMI?
A
- primary percutaneous coronary intervention (PCI)
2. Fibronolytics (in STEMI, the thrombus is heavily laced with fibrin)
23
Q
What are the goals of therapy in reperfusion?
A
- decrease mortality and complications
- reduce or contain infarct size
- salvage functioning myocardium and prevent remodelling
- re-establish potency of the infarct-related artery (clear occlusion, reestablish flow of coronary blood)
24
Q
What is the recommended method of reperfusion?
A
- primary PCI (when it can be performed in a timely fashion)
- ideal medical contact to device time of <90 minutes should be targeted for primary PCI
- if fibrinolytic therapy is chosen as the reperfusion strategy, it should be administered within 30 minutes of hospital arrival
25
Describe the process of a primary PCI?
- diagnostic catheter is placed and advanced through the femoral artery to the aorta and the coronary arteries
- contrast dye is injected once the catheter is in place. X-rays are taken to locate the exact location of coronary occlusion
- a balloon catheter (with or without a stent mounted) is advanced to the blockage site. Once at the site, the balloon is inflated for a few seconds to open the blocked coronary
- the stents are left in place to keep the coronary vessel open
26
How long should someone be on anti-platelet therapy after a PCI?
- should be on anti-platelet therapy for a minimum of 1 year after a PCI
27
What is the TIMI grade flow? What TIMI blood flow do we want to achieve?
- adopted scoring system from 0-3 referring to the level of coronary blood flow assessed during a PCI
- we want to achieve TIMI 3 blood flow for complete perfusion
28
What is the TIMI grade flow? What TIMI blood flow do we want to achieve?
- adopted scoring system from 0-3 referring to the level of coronary blood flow assessed during a PCI
- we want to achieve TIMI 3 blood flow for complete perfusion
29
Angioplasty without _____ is rarely used in the setting of the ACS now
stenting
| ---- PCI procedures almost always involve a bare metal send or a drug eluting stent
30
What is a drug eluting stent and why is it most commonly used?
- a stent that has anti proliferative drugs coating on the stent scaffold, which is released slowly over time to prevent restenosis
- --- body will naturally want to endotheliaze around the stent- this is why drug coating is important
31
Patients who ave received a DES will require dual-antiplatelet therapy for a minimum of _____
1 year
32
What is the timeframe that fibrinolytics need to be given for the greatest mortality benefit
needs to be given within 0-2 hours (target time of 30 minutes)
33
Why are fibrinolytics not administered to NATEMI/UA patients?
- this goes back to the pathology of clotting- in STEMI there is a big thrombus made up of heavy fibrin, which is not found in NSTEMI/UA
- fibrinolytic add risk of bleeding and is not worth this risk in anything but STEMI
34
What fibrinolytic should be given due to its high specificity?
- tenecteplase when possible should be given as a single IV bolus for 5 seconds
35
What are the main benefits of giving tenecteplase over over fibrinolytics?
- there are 20% fewer major non-cerebral bleeds
- little effect on blood pressure
- most fibrin-specfic agent
36
What are the absolute contraindications to fibrolytics?
- any prior ICH
- known structural cerebral vascular lesion
- known malignant intracranial neoplasm
- ischemic stroke within 3 months
- suspected aortic dissection
- active bleeding
- significant closed head or facial trauma within 3 months
- severe uncontrolled hypertension
- for streptokinase, prior treatment within the previous 6 months
37
______ are the cornerstone therapy in STEMI management
antithrombotics (anti platelets and anticoagulants)
38
When is the use of heparin appropriate for use in ACS with someone ?
- usually initiated on presentation and discontinued after PCI
39
What should be given to STEMI patients undergoing primary PCI?
- ASA 162-325 mg po should be given before PCI PLUS
a loading dose of a P2Y12 receptor inhibitor as early as possible before PCI
--- clopridogrel 600 mg, prasugrel 60 mg or ticagrelor 180 mg ---- ticagrelor is the 1st recommended
40
How long should a P2Y12 inhibitor be used after ACS?
- should be used for the minimum of 1 year (can be used even more though)
41
What antithrombotics are appropriate to use in STEMI patients receiving fibrinolytics?
- ASA 162-325 mg po should be given on presentation PLUS
| - clopridogrel loading dose along with clopridogrel 75 mg po daily for 14 days
42
What is the appropriate use of heparin in STEMI patients receiving fibrinolytics?
- LMWH or UFH should be initiated at the time of fibrinolysis and continued for a minimum of 48 hours and up to 8 days (or until revascularization)
43
What is enoxaprin?
- most commonly used LMWH
44
What heparin needs to be monitored more regularly?
LMWH needs to be monitored more often
| - UFH should be used in those that we are not sure of their dose and in renal impairment and the obese
45
Should enoxaprin always be given as an IV bolus?
- NO
| - it should only be given as a bolus dose in STEMI patients under the age of 75
46
When is the use of heparin indicated in patients?
- should be used in patients >149 kg (little evidence to support LMWH in these patients)
- used for those with renal impairment, CrCl <30 mL/min
47
Clinical trials suggest better efficacy profile with what combination of drugs when compared to ASA+clopridogrel in patients with STEMI undergoing primary PCI
ASA and prasugrel
| ASA and ticagrelor
48
Prasugrel should not be used in what patients?
in those with a history of stroke or TIA due to higher rates of major bleeding in these populations
49
Triple therapy of _______ may be indicated in STEMI patients with low ejection fraction or if the patient has a concurrent AF
DAPT and warfarin
50
What needs to be monitored in a patient after repercussion therapy is done?
Need to monitor for EFFICACY
- signs and sx of ongoing chest pain, ECG changes, serial monitoring of biomarkers
- stent thrombosis
- complications: arrhythmias, HF, pericarditis
Need to monitor for SAFETY
- major and minor bleeding complications
- clinical signs of bleeding include bloody stools, melon, hematuria, hematemesis, bruising, and oozing from arterial or venous puncture sites
51
What are some of the main complications associated with a STEMI?
1. Heart failure
2. Cardiogenic shock
3. Arrhythmias
4. Pericarditis
52
What causes heart failure after an MI?
- LV myocardium may be ischemic, stunned, hibernating or irrevocably injured after MI
53
What is used to assess LV ejection fraction?
echocardiography
| - intervention is required in those with a LVEF <40%
54
What causes cariogenic shock after an MI?
- decreased cardiac output and evidence of tissue hypoxia in presence of adequate intravascular volume
- this is often due to an extensive LV infarction
- can also be due to systolic, diastolic and valvular dysfunction
- incidence ~10% of hospitalized STEMI patients
55
What causes an arrhythmia to arise post MI?
- due to ischemia and severe HF
- there will be some rhythm changes as you are re-gaining oxygen to myocardium
- ventricular arrhythmias are more probable in the peri-infarction period
56
What is the role that beta blockers will play post MI?
- increase myocardial salvage in the infarct area
- prevent extension of infarction by reducing oxygen consumption/demand
- decrease cardiovascular mortality, recurrent nonfatal MI and all-cause mortality
57
When are beta blockers indicated after an MI?
- should be initiated within 24 hours post MI
58
What is the goal HR when giving a beta blocker post MI?
55-60 bpm
59
What are the contraindications to beta blockers?
- hypotension (systolic BP <90)
- bradycardia (HR <50 bp)
- acute HF
- cardiogenic shock
- asthma
- 2nd or 3rd degree AV block
60
What is the role of a ACEI after an event?
- minimize ventricular remodeling
- reduce oxygen demand and myocardial wall stress by reducing after load or preload
- reduction in cardiovascular mortality and morbidity
61
The benefit of and ACEI is greatest in what population?
- anterior infarction, HF (LVEF <40%), patients with diabetes or CKD
- should be initiated win 24 hours of an MI once BP is stabilized
62
What groups are ACEIs CI'ed in?
- in those with renal impairment and hyperkalemia
63
What is important to monitor for with an ACEI?
- SCr, electrolytes, watch for hyperkalemia (K>5.5) especial with concurrent spironolactone
64
What is evolovumab?
- its a monoclonal antibody (biologic) that inhibitrs PCSK9 - lowers the LDL
65
When would an aldosterone antagonist like spironolactone be used?
- may be indicated if the patient has severe LV dysfunction (EF <40%)
66
When would aldosterone antagonists be contraindicated in patients?
caution in patients with CrCl <30 ml/min and K 5 mEq
| - check the potassium at baseline and within 1 week of initiation
67
What are some of the non-pharamcological things that can be done to help patients manage after ACS?
- cardiac rehab program
- weight management (BMI 18.5-25, waist circumference, goal of 5-10% weight reduction)
- physical exercise (goal of 30-60 minutes of moderate activity)
- implantable cardioverter/defibrillator assessment for patients with ongoing LV dysfunction
- depression screening/stress management
