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What is the maximum total dose of Alteplase that can be given?
What is the maximum total dose of Alteplase that can be given?
Reteplase is administered as a single dose of 10 units IV over 2 minutes.
Reteplase is administered as a single dose of 10 units IV over 2 minutes.
False
What is the preferred dosage form of aspirin for immediate administration in patients receiving fibrinolytic therapy?
What is the preferred dosage form of aspirin for immediate administration in patients receiving fibrinolytic therapy?
non-enteric-coated aspirin
The risk of __________ is higher with streptokinase than with fibrin-specific agents.
The risk of __________ is higher with streptokinase than with fibrin-specific agents.
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What is the recommended maintenance dose of aspirin after PCI?
What is the recommended maintenance dose of aspirin after PCI?
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Patients receiving fibrinolytic therapy should continue other NSAIDs at the time of STEMI.
Patients receiving fibrinolytic therapy should continue other NSAIDs at the time of STEMI.
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Match the following fibrinolytics with their administration methods:
Match the following fibrinolytics with their administration methods:
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The most frequent side effects of aspirin include __________ and __________.
The most frequent side effects of aspirin include __________ and __________.
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What is the primary diagnosis tool for acute coronary syndrome (ACS)?
What is the primary diagnosis tool for acute coronary syndrome (ACS)?
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Biochemical markers are unnecessary if the ECG shows signs of ischemia.
Biochemical markers are unnecessary if the ECG shows signs of ischemia.
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What are the cardiac biomarkers used to confirm a diagnosis of myocardial infarction?
What are the cardiac biomarkers used to confirm a diagnosis of myocardial infarction?
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The short-term goal of treatment for myocardial infarction includes early restoration of blood flow to the __________ artery.
The short-term goal of treatment for myocardial infarction includes early restoration of blood flow to the __________ artery.
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What is the recommended reperfusion treatment for STEMI within 12 hours of symptom onset?
What is the recommended reperfusion treatment for STEMI within 12 hours of symptom onset?
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Match the following treatment goals with their correct descriptions:
Match the following treatment goals with their correct descriptions:
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Early coronary angiography is only recommended for high-risk patients with NSTE-ACS.
Early coronary angiography is only recommended for high-risk patients with NSTE-ACS.
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Patients are stratified into low, medium, or high risk based on symptoms, past medical history, __________, and biomarkers.
Patients are stratified into low, medium, or high risk based on symptoms, past medical history, __________, and biomarkers.
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What is the classification of Acute Coronary Syndrome based on electrocardiographic changes?
What is the classification of Acute Coronary Syndrome based on electrocardiographic changes?
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Unstable angina is classified under non-ST-segment-elevation myocardial infarction (NSTEMI).
Unstable angina is classified under non-ST-segment-elevation myocardial infarction (NSTEMI).
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What are the predominant symptoms experienced during acute coronary syndrome?
What are the predominant symptoms experienced during acute coronary syndrome?
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The formation of a fibrin clot during acute coronary syndrome is composed of fibrin strands, cross-linked platelets, and trapped _____ cells.
The formation of a fibrin clot during acute coronary syndrome is composed of fibrin strands, cross-linked platelets, and trapped _____ cells.
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Which symptom is NOT typically associated with acute coronary syndrome?
Which symptom is NOT typically associated with acute coronary syndrome?
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Match the following complications of myocardial infarction with their descriptions:
Match the following complications of myocardial infarction with their descriptions:
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What triggers the activation of platelets in acute coronary syndrome?
What triggers the activation of platelets in acute coronary syndrome?
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Ventricular remodeling after a myocardial infarction is characterized by right ventricular dilation.
Ventricular remodeling after a myocardial infarction is characterized by right ventricular dilation.
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What is the target activated partial thromboplastin time (aPTT) for STE-ACS treatment with fibrinolytics?
What is the target activated partial thromboplastin time (aPTT) for STE-ACS treatment with fibrinolytics?
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Enoxaparin should be administered every 12 hours for all patients regardless of age or renal function.
Enoxaparin should be administered every 12 hours for all patients regardless of age or renal function.
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What is the initial dose of bivalirudin for PCI in STEMI?
What is the initial dose of bivalirudin for PCI in STEMI?
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The reduction of heart rate by β-blockers improves _________ time, enhancing ventricular filling.
The reduction of heart rate by β-blockers improves _________ time, enhancing ventricular filling.
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Match the anticoagulants with their respective dosing regimens:
Match the anticoagulants with their respective dosing regimens:
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Which of the following is true regarding β-blockers in patients with MI?
Which of the following is true regarding β-blockers in patients with MI?
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Anticoagulant therapy can be administered for up to 48 hours when no reperfusion therapy is performed.
Anticoagulant therapy can be administered for up to 48 hours when no reperfusion therapy is performed.
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How long should enoxaparin be continued during hospitalization?
How long should enoxaparin be continued during hospitalization?
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What is the target resting heart rate for patients taking β-blockers?
What is the target resting heart rate for patients taking β-blockers?
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Initial administration of β-blockers is appropriate for patients presenting with acute heart failure.
Initial administration of β-blockers is appropriate for patients presenting with acute heart failure.
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What high-intensity statins should be administered to all patients prior to PCI?
What high-intensity statins should be administered to all patients prior to PCI?
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The initial dose of Metoprolol is ___ mg by slow IV bolus.
The initial dose of Metoprolol is ___ mg by slow IV bolus.
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What is a side effect of early administration of β-blockers in acute coronary syndrome?
What is a side effect of early administration of β-blockers in acute coronary syndrome?
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Match the β-blockers with their corresponding administration details:
Match the β-blockers with their corresponding administration details:
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What treatment is indicated for patients with ACS who have persistent ischemic discomfort?
What treatment is indicated for patients with ACS who have persistent ischemic discomfort?
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Patients with LV systolic dysfunction and LVEF of 40% or less should continue β-blockers ___.
Patients with LV systolic dysfunction and LVEF of 40% or less should continue β-blockers ___.
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Study Notes
Acute Coronary Syndromes (ACS)
- ACS encompasses all syndromes compatible with acute myocardial ischemia stemming from an imbalance between myocardial oxygen demand and supply.
- Classified into:
- ST-segment-elevation myocardial infarction (STEMI)
- Non–ST-segment-elevation ACS (NSTE-ACS)
- Non–ST-segment-elevation MI (NSTEMI)
- Unstable angina (UA)
Pathophysiology
- Endothelial dysfunction, inflammation and fatty streaks contribute to the development of atherosclerotic coronary artery plaques.
- Rupture of a plaque exposes collagen and tissue factor, inducing platelet adhesion and activation.
- Platelets release adenosine diphosphate (ADP) and thromboxane A2, leading to vasoconstriction and activation.
- Glycoprotein IIb/IIIa receptor conformation changes, enabling platelets to cross-link through fibrinogen bridges.
- Activation of the extrinsic coagulation cascade occurs due to exposure of blood to the thrombogenic lipid core and endothelium.
- This leads to the formation of a fibrin clot composed of fibrin strands, platelets and trapped red blood cells.
- Ventricular remodeling post-MI is characterized by left ventricular (LV) dilation and reduced pumping function, leading to heart failure (HF).
Clinical Presentation
- Predominant symptom is midline anterior chest pain, often at rest.
- Severe, new-onset angina or increasing angina lasting at least 20 minutes.
- Discomfort may radiate to the shoulder, left arm, back or jaw.
- Accompanying symptoms can include nausea, vomiting, diaphoresis and shortness of breath.
Diagnosis
- Obtain 12-lead ECG within 10 minutes of presentation.
- Key findings indicating myocardial ischemia or MI are STE, ST-segment depression and T-wave inversion.
- Some patients with myocardial ischemia exhibit no ECG changes, requiring biochemical markers and coronary artery disease risk factors evaluation.
- MI diagnosis is confirmed with rising and/or falling cardiac biomarkers (mainly troponin T or I) along with ECG changes.
- Blood samples are typically taken once in the emergency department and again 3 to 6 hours after symptom onset.
Treatment Goals
- Short-term goals include:
- Early restoration of blood flow to the infarct-related artery.
- Prevention of death and other complications.
- Prevention of coronary artery reocclusion.
- Relief of ischemic chest discomfort.
- Resolution of ST-segment and T-wave changes on ECG.
- Long-term goals involve controlling cardiovascular (CV) risk factors, preventing additional CV events and enhancing quality of life.
Nonpharmacologic Therapy
- For STEMI patients presenting within 12 hours of symptom onset, early reperfusion with primary PCI of the infarct artery within 90 minutes of first medical contact is the preferred treatment.
- For NSTE-ACS patients, practice guidelines recommend early (within 24 hours) coronary angiography and revascularization with either PCI or CABG surgery as early treatment for high-risk patients.
Pharmacologic Therapy
- Fibrinolytics
- Fibrinolytics are used to dissolve blood clots and restore blood flow to the heart.
- They are given intravenously (IV) and should be administered as soon as possible after the onset of symptoms.
- Available therapies include:
- Alteplase
- Reteplase
- Tenecteplase
- Streptokinase
- ICH and major bleeding are the most serious side effects.
- Aspirin
- Administer aspirin to all patients without contraindications within 24 hours before or after hospital arrival.
- Provides additional mortality benefit in patients receiving fibrinolytic therapy.
- Give non–enteric-coated aspirin 162 to 325 mg regardless of the reperfusion strategy being considered.
- Patients undergoing PCI not previously taking aspirin should receive 325-mg non–enteric-coated aspirin.
- A daily maintenance dose of 75 to 162 mg is recommended thereafter and should be continued indefinitely.
- Low-dose aspirin (81 mg daily) is preferred following PCI due to increased bleeding risk when combined with a P2Y12 inhibitor.
- Discontinue other NSAIDs and COX-2 selective inhibitors at the time of STEMI.
- The most frequent side effects of aspirin include dyspepsia and nausea.
- Unfractionated Heparin (UFH)
- Administer IV UFH to all patients with STEMI or NSTE-ACS.
- Titrate to maintain a target aPTT of 1.5 to 2 times control.
- Measure the first aPTT at 3 hours in patients with STE-ACS who are treated with fibrinolytics and at 4 to 6 hours in patients not receiving thrombolytics or undergoing primary PCI.
- Continue for 48 hours or until the end of PCI.
- Low-Molecular-Weight Heparin (LMWH)
- Encoxaparin: 1 mg/kg SC every 12 hours (creatinine clearance [Clcr] ≥30 mL/min) or once every 24 hours if Clcr is impaired.
- For STEMI receiving fibrinolytics: 30-mg IV bolus followed immediately by 1 mg/kg SC every 12 hours if younger than 75 years, 0.75 mg/kg SC every 12 hours for patients 75 years and older.
- Continue enoxaparin throughout hospitalization or up to 8 days.
- Direct Thrombin Inhibitor
- Bivalirudin: 0.75 mg/kg IV bolus, followed by 1.75 mg/kg/h infusion.
- Discontinue at the end of PCI or continue at 0.25 mg/kg/h if prolonged anticoagulation is necessary.
- Factor Xa Inhibitor
- Fondaparinux: 2.5 mg IV bolus followed by 2.5 mg SC once daily starting on hospital day 2.
- For patients undergoing PCI, discontinue anticoagulation immediately after the procedure.
- β-Adrenergic Blockers
- Benefits include reduced heart rate, myocardial contractility and BP, decreasing myocardial oxygen demand.
- Reduce risk for recurrent ischemia, infarct size, reinfarction and ventricular arrhythmias.
- Β-blockers (particularly IV) should be limited to patients presenting with hypertension or signs of myocardial ischemia who do not have signs/symptoms of acute HF.
- Usual doses include:
- Metoprolol
- Propranolol
- Atenolol
- The most serious side effects early include hypotension, acute HF, bradycardia and heart block.
- Continue β-blockers for at least 3 years in patients with normal LV function and indefinitely in patients with LV systolic dysfunction and LVEF of 40% or less.
- Statins
- Administer a high-intensity statin to all patients prior to PCI, regardless of prior lipid-lowering therapy.
- Nitrates
- NTG causes venodilation, lowering preload and myocardial oxygen demand.
- Arterial vasodilation may lower BP, reducing myocardial oxygen demand.
- Arterial dilation also relieves coronary artery vasospasm and improves myocardial blood flow and oxygenation.
- Administer one SL NTG tablet (0.4 mg) every 5 minutes for up to three doses to relieve chest pain and myocardial ischemia.
- IV NTG is indicated for patients with an ACS without contraindications and who have persistent ischemic discomfort, HF or uncontrolled high BP.
General Information
- Patients presenting with symptoms suggestive of ACS should undergo prompt evaluation and treatment.
- Timely and accurate diagnosis and management of ACS are crucial for improving patient outcomes and reducing mortality.
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Description
Explore the critical aspects of Acute Coronary Syndromes (ACS), including its classifications, such as STEMI and NSTE-ACS. Understand the pathophysiological mechanisms involved, including endothelial dysfunction and platelet activation. This quiz will enhance your knowledge of myocardial ischemia and its implications.
