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Questions and Answers

What does NSTEMI stand for in the context of acute coronary syndrome?

  • Non-ST-Elevation Myocardial Infarction (correct)
  • Non-ST-Temporal Myocardial Injury
  • New ST-Elevation Myocardial Infarction
  • Narrowed ST-Elevation Myocardial Ischemia

    • What is the primary cause of the imbalance in myocardial oxygen supply and demand in acute coronary syndrome?

  • Severe emotional stress
  • Coronary artery thrombosis (correct)
  • High blood pressure levels
  • Increased physical activity

    • Which condition is NOT classified under non-ST elevation acute coronary syndromes?

  • Both A and B
  • Unstable Angina
  • Stable Angina (correct)
  • NSTEMI

    • In unstable angina, what typically signifies a worsening of the patient's condition?

    <p>Occurrence at rest or low level of activity</p> Signup and view all the answers

    Which option best describes the nature of the plaque formation in acute coronary syndrome?

    <p>Formation leading to coronary artery thrombosis</p> Signup and view all the answers

    What is considered a severe chest pain characteristic indicating a potential NSTEMI?

    <p>Occurs at rest and lasts more than 10 minutes.</p> Signup and view all the answers

    Which of the following is a preferred biomarker for diagnosing NSTEMI?

    <p>Cardiac Troponin 1 (cTn)</p> Signup and view all the answers

    In the context of diagnosing NSTEMI, which assessment is not typically performed?

    <p>Imaging studies like X-rays</p> Signup and view all the answers

    What condition is indicated by cardiac troponin 1 levels being elevated?

    <p>Non-ST elevation myocardial infarction (NSTEMI)</p> Signup and view all the answers

    What is the main initial treatment for patients with NSTE-ACS?

    <p>Anti-ischemic therapy, bed rest, and oxygen</p> Signup and view all the answers

    Which medication is considered the cornerstone of anti-thrombotic treatment in NSTE-ACS?

    <p>Aspirin</p> Signup and view all the answers

    Which of the following anticoagulants has been found to be superior to unfractionated heparin in reducing recurrent cardiac events?

    <p>Enoxaparin</p> Signup and view all the answers

    What monitoring is essential for patients admitted with NSTE-ACS?

    <p>Continuous ECG monitoring for ST-segment deviation and arrhythmias</p> Signup and view all the answers

    Which anticoagulant is a direct thrombin inhibitor suitable for use prior to or during PCI?

    <p>Bivalirudin</p> Signup and view all the answers

    What is the first step in the invasive treatment strategy for acute coronary syndrome?

    <p>Coronary arteriography within 48 hours</p> Signup and view all the answers

    Which of the following scenarios would prompt a conservative treatment strategy to become more invasive?

    <p>Positive biomarkers of necrosis</p> Signup and view all the answers

    Which of the following is NOT a component of the long-term medical management of acute coronary syndrome?

    <p>Increased physical activity</p> Signup and view all the answers

    In a conservative management strategy, when is coronary arteriography performed?

    <p>If ST-segment changes recur</p> Signup and view all the answers

    What primarily characterizes Prinzmetal’s variant angina?

    <p>Occurs at rest and is associated with ST segment elevation.</p> Signup and view all the answers

    Which risk factor is most commonly associated with Prinzmetal's variant angina?

    <p>Cigarette smoking</p> Signup and view all the answers

    What are the provocative tests used to diagnose Prinzmetal's variant angina?

    <p>Hyperventilation and intercoronary acetylcholine</p> Signup and view all the answers

    Which treatment is specifically recommended for Prinzmetal's variant angina?

    <p>Nitrates and calcium channel blockers</p> Signup and view all the answers

    What should be avoided in the treatment of Prinzmetal's variant angina due to possible adverse effects?

    <p>Aspirin</p> Signup and view all the answers

    What is the prognosis for patients diagnosed with Prinzmetal’s variant angina after five years?

    <p>90-95% survival rate</p> Signup and view all the answers

    Which of the following factors is NOT considered a common risk factor for acute plaque rupture?

    <p>Hypercoagulability</p> Signup and view all the answers

    What characterizes the chest pain often associated with STEMI?

    <p>Heavy squeezing and crushing</p> Signup and view all the answers

    Among the following, which is identified as a precipitating factor for STEMI?

    <p>Vigorous physical exercise</p> Signup and view all the answers

    What type of histological characteristic might indicate a plaque’s susceptibility to rupture?

    <p>Rich lipid core and thin fibrous cap</p> Signup and view all the answers

    Which of the following is NOT a differential diagnosis for chest pain suggestive of STEMI?

    <p>Pulmonary embolism</p> Signup and view all the answers

    Which symptom is commonly associated with STEMI?

    <p>Chest Pain characterized as heavy squeezing</p> Signup and view all the answers

    What is a characteristic feature of the location of chest pain during a STEMI?

    <p>Central chest and/or epigastrium</p> Signup and view all the answers

    Which factor is a known precipitating cause of STEMI?

    <p>Vigorous physical exercise</p> Signup and view all the answers

    Which associated symptom might indicate impending doom in a STEMI patient?

    <p>Sense of impending doom</p> Signup and view all the answers

    During a physical examination of a patient with STEMI, which finding is likely?

    <p>Diaphoretic and anxious</p> Signup and view all the answers

    Which differential diagnosis is relevant for evaluating chest pain suggestive of STEMI?

    <p>Acute aortic dissection</p> Signup and view all the answers

    What is the maximum target delay for obtaining a 12-lead ECG after the first medical contact?

    <p>10 minutes</p> Signup and view all the answers

    Which of the following biomarkers is typically elevated in patients experiencing STEMI?

    <p>Cardiac-specific troponin T (cTnT)</p> Signup and view all the answers

    What technique helps in detecting the presence of wall motion abnormalities during an echocardiogram?

    <p>Two-dimensional echocardiography</p> Signup and view all the answers

    What complication can Doppler echocardiography help detect following STEMI?

    <p>Mitral regurgitation</p> Signup and view all the answers

    When are cardiac biomarkers detectable in the peripheral blood?

    <p>Once overflow from cardiac lymphatics occurs</p> Signup and view all the answers

    What is the role of cardiac MRI in the assessment of myocardial infarction?

    <p>To utilize a technique referred to as late enhancement</p> Signup and view all the answers

    What other imaging technique, besides echocardiography, is mentioned for myocardial assessment?

    <p>Radionuclide imaging</p> Signup and view all the answers

    What is defined as the first medical contact (FMC)?

    <p>The time a patient is assessed by medical personnel who can interpret the ECH.</p> Signup and view all the answers

    What does the term 'rescue PCI' refer to?

    <p>Emergent PCI performed after failed fibrinolysis.</p> Signup and view all the answers

    What characterizes the 'primary PCI' approach?

    <p>Immediate PCI without previous fibrinolysis.</p> Signup and view all the answers

    What does the pharmacoinvasive strategy combine?

    <p>Fibrinolysis with either rescue PCI or routine early PCI.</p> Signup and view all the answers

    What signifies a STEMI diagnosis?

    <p>Presence of ischemic symptoms and ST-segment elevation.</p> Signup and view all the answers

    What is the time goal for initiating PCI following first medical contact?

    <p>120 minutes</p> Signup and view all the answers

    Which complication may arise from coronary artery reocclusion after fibrinolysis?

    <p>Arrhythmias</p> Signup and view all the answers

    What is the maximum recommended door-to-needle time for fibrinolysis?

    <p>90 minutes</p> Signup and view all the answers

    What is one indication for urgent PCI during hospitalization?

    <p>Positive exercise stress test</p> Signup and view all the answers

    What is one of the major goals in the management of patients presenting with acute coronary syndrome?

    <p>Minimize time to reperfusion therapy</p> Signup and view all the answers

    What is the dietary recommendation for fat intake during the first 4–12 hours?

    <p>≤30%</p> Signup and view all the answers

    Which medication is indicated for sedation to manage inactivity?

    <p>Lorazepam</p> Signup and view all the answers

    What is the initial dose of Nitroglycerin during the first 24-48 hours?

    <p>5-10 mcg/min</p> Signup and view all the answers

    What type of diet is recommended to manage bowel health?

    <p>Diet rich in bulk</p> Signup and view all the answers

    Which of the following is NOT recommended for patients with STEMI?

    <p>CCBs</p> Signup and view all the answers

    What is the primary reason for the use of Aspirin in patients experiencing STEMI?

    <p>To rapidly inhibit Cox-1 in platelets</p> Signup and view all the answers

    Which medication is administered to STEMI patients who cannot tolerate ACE inhibitors?

    <p>Angiotensin receptor blockers (ARB)</p> Signup and view all the answers

    How does beta-adrenoceptor blockade affect myocardial oxygen supply and demand?

    <p>It improves the supply-demand relationship</p> Signup and view all the answers

    What is the maximum initial bolus dose of Unfractionated Heparin (UFH) for treating STEMI patients?

    <p>60 U/kg, maximum 4000 U</p> Signup and view all the answers

    Which characteristic is essential for administering Mineralocorticoid Receptor Antagonists in STEMI patients?

    <p>Creatinine level in men ≥2.5 mg/dL</p> Signup and view all the answers

    What advantage does Enoxaparin (LMWH) offer compared to Unfractionated Heparin?

    <p>High bioavailability with subcutaneous administration</p> Signup and view all the answers

    What is a common treatment recommendation in the early hours following STEMI?

    <p>Bed rest for the first 6-12 hours</p> Signup and view all the answers

    Which newer P2Y12 ADP receptor antagonist is known to be more effective than Clopidogrel?

    <p>Prasugrel</p> Signup and view all the answers

    Study Notes

    Acute Coronary Syndrome (ACS)

    • ACS represents a spectrum of conditions associated with sudden reduced blood flow to the heart.

    Non-ST-Elevation Myocardial Infarction (NSTEMI)

    • NSTEMI is a type of ACS characterized by partial blockage in the coronary arteries leading to heart muscle damage.

    Unstable Angina

    • Unstable angina is another form of ACS, indicating significant heart stress without significant heart muscle damage.

    Pathophysiology

    • ACS occurs due to an imbalance between myocardial oxygen supply and demand, leading to ischemia.

    Causes of ACS

    • Plaque formation in coronary arteries can lead to blockage.
    • Coronary artery thrombosis results from plaque rupture, impeding blood flow.

    Key Points

    • Immediate recognition and treatment of ACS are crucial to prevent severe heart damage.
    • Risk factors for ACS include high cholesterol, hypertension, smoking, diabetes, and sedentary lifestyle.

    Diagnosis Overview

    • Diagnosis involves a combination of history, physical examination, age assessment, ECG, and cardiac troponins (cTns) levels.

    History and Physical Examination

    • Severe chest pain is a critical symptom, characterized by:
      • Occurrence at rest or with minimal exertion, lasting longer than 10 minutes.
      • Recent onset of symptoms, specifically within the past two weeks.
      • Crescendo pattern indicating an increase in severity, duration, or frequency compared to previous episodes.

    Electrocardiogram (ECG)

    • ECG evaluation is essential for diagnosing cardiac-related issues and should be performed alongside other diagnostic tools.

    Cardiac Biomarkers

    • Cardiac Troponin 1 (cTn) is a crucial biomarker for identifying myocardial necrosis, especially in NSTEMI (Non-ST Elevation Myocardial Infarction).
    • cTn is highly sensitive and relatively specific, making it the preferred marker for distinguishing NSTEMI from unstable angina (UA).
    • Elevated cTn levels indicate ongoing myocardial injury and are vital for confirming NSTEMI diagnosis.

    Medical Management of NSTE-ACS

    • Patients identified with NSTE-ACS based on clinical features, cardiac troponin (cTn) levels, or ST-T-wave changes on ECG require hospital admission.
    • Continuous ECG monitoring is essential for observing ST-segment deviation and cardiac arrhythmias, preferably in a specialized cardiac unit.
    • Bed rest is prescribed, along with oxygen therapy for patients exhibiting hypoxemia.

    Anti-ischemic Treatment

    • The initial treatment includes anti-ischemic measures, along with bed rest and oxygen for hypoxemic patients.

    Anti-thrombotic Therapy

    • Antiplatelet and anticoagulant therapy are crucial components of NSTE-ACS treatment.
    • Initial antiplatelet treatment includes aspirin administration.

    Anticoagulant Options

    • Four main parenteral anticoagulant therapies can be utilized alongside antiplatelet agents:
      • Unfractionated heparin (UFH) has historically been essential in managing NSTE-ACS.
      • Enoxaparin, a low-molecular-weight heparin (LMWH), has shown superior effectiveness over UFH in reducing recurrent cardiac events.
      • Bivalirudin acts as a direct thrombin inhibitor, achieving similar efficacy to UFH or LMWH, particularly used during percutaneous coronary intervention (PCI).
      • Fondaparinux is a synthetic factor Xa inhibitor, comparable in effectiveness to enoxaparin but associated with a lower risk of major bleeding events.

    Invasive vs Conservative Treatment Strategies

    • Invasive Strategy: Utilizes anti-ischemic and antithrombotic medications followed by coronary arteriography within 48 hours after presentation. This approach leads to coronary revascularization through PCI (Percutaneous Coronary Intervention) or CABG (Coronary Artery Bypass Grafting).
    • Conservative Strategy: Starts with anti-ischemic and antithrombotic drugs, followed by a selective invasive approach. Patients are closely monitored, with coronary arteriography indicated if specific conditions arise, such as:
      • Presence of epicardial coronary stenosis on coronary computed tomography angiography.
      • Recurrence of rest pain or ST-segment changes.
      • Positive biomarkers indicating myocardial necrosis.
      • Severe ischemia demonstrated on a stress test.

    Long-Term Management

    • Medical Management: Involves a structured approach to patient care:
      • Dual antiplatelet therapy with Aspirin (ASA) and P2Y12 inhibitors for 12 months; if the patient is at high risk of bleeding, monotherapy may be initiated afterwards.
      • Use of Beta-Blockers to manage heart rate and workload.
      • ACE inhibitors (ACEi) or Angiotensin II Receptor Blockers (ARBs) to help regulate blood pressure.
      • Lipid-lowering therapy aimed at achieving target LDL cholesterol levels (LDL-C).

    Characteristics of Prinzmetal's Variant Angina

    • Occurs at rest, not triggered by exertion, and is linked to ST segment elevation on ECG.
    • Primarily caused by focal spasm of epicardial coronary arteries.

    Clinical Profile

    • Predominantly affects younger individuals with minimal risk factors other than cigarette smoking.
    • Cardiac exam typically shows unremarkable findings.
    • Diagnosis involves observing transient ST-segment elevation associated with rest pain.

    Angiographic Manifestations

    • Diagnostic hallmark: transient coronary spasm detected during angiography.
    • Provocative tests include hyperventilation and intercoronary acetylcholine (Ach) to induce and confirm focal coronary stenosis or provoke rest angina with ST-segment elevation.

    Treatment and Management

    • Primary medications include nitrates and calcium channel blockers (CCB).
    • Aspirin is contraindicated as it may worsen ischemic episodes due to increased sensitivity of coronary tone to prostacyclin synthesis changes.
    • Statins are beneficial in reducing adverse effects related to coronary artery disease.
    • Coronary revascularization is considered for patients with discrete, flow-limiting, proximal fixed obstructive lesions.

    Prognosis

    • The 5-year survival rate is high, ranging from 90% to 95%.
    • Initial phase lasts about 6 months, marked by frequent angina episodes and increased risk of cardiac events.

    Pathophysiology of Acute Plaque Rupture

    • Risk factors for acute plaque rupture include hypertension (HTN), smoking, lipid accumulation, multiple coronary risk factors, and unstable angina (UA).
    • Less common factors involve hypercoagulability, collagen vascular disease, cocaine abuse, and intracardiac thrombi or masses which can cause coronary emboli.
    • Histological characteristics of plaques prone to disruption consist of a rich lipid core and a thin fibrous cap.
    • Rarely, STEMI may be induced by coronary artery occlusion from coronary emboli, congenital abnormalities, coronary spasm, or systemic inflammatory diseases.

    Clinical Presentation of STEMI

    • About half of STEMI cases exhibit precipitating factors such as vigorous physical exercise, emotional stress, or significant medical/surgical illness.
    • Common symptoms include:
      • Chest Pain:
        • Character: Typically described as deep, heavy, squeezing, and crushing; can also present as stabbing or burning.
        • Location: Mainly in the central chest and/or epigastrium; may radiate to arms and occipital area, but not below the umbilicus or trapezius.
      • Associated symptoms: Weakness, nausea, sweating, vomiting, anxiety, and a profound sense of impending doom.
      • Less common signs include sudden loss of consciousness (LOC), confusion, profound weakness, arrhythmias, peripheral embolism, and unexplained drops in arterial pressure.

    Differential Diagnosis

    • Conditions to consider in differential diagnosis include:
      • Acute pericarditis
      • Acute aortic dissection
      • Costochondritis
      • Gastrointestinal disorders

    Pathophysiology and Clinical Presentation

    • Precipitating factors are present in around half of STEMI cases; common triggers include vigorous physical exercise, emotional stress, and medical or surgical conditions.
    • Typical chest pain associated with STEMI is described as deep, heavy, squeezing, or crushing in nature; may vary and can also be stabbing or burning.
    • Pain is primarily located in the central chest and/or epigastric region, sometimes radiating to the arms and occipital area; pain never radiates below the umbilicus or to the trapezius region.
    • Associated symptoms may include weakness, nausea, sweating, vomiting, anxiety, and a profound sense of impending doom.
    • Less common symptoms can occur, including sudden loss of consciousness (LOC), confusion, severe weakness, arrhythmias, peripheral embolism, and unexplained drop in arterial pressure.
    • Differential diagnoses to consider include acute pericarditis, acute aortic dissection, costochondritis, and gastrointestinal disorders.

    Physical Examination Findings

    • Patients often present as anxious, restless, and diaphoretic.
    • Patients may exhibit behaviors aimed at pain relief such as moving in bed, changing positions, or stretching.
    • Anterior STEMI is associated with sympathetic nervous system hyperactivity, resulting in tachycardia and hypertension.
    • Inferior STEMI often presents with parasympathetic hyperactivity, leading to bradycardia and/or hypotension.

    Electrocardiogram

    • A 12-lead ECG recording should be done at first medical contact (FMC) with a maximum delay of 10 minutes.
    • ST-segment elevation can evolve to Q waves in most patients presenting with an acute myocardial infarction (MI).
    • Detection of transmural MI occurs with the presence of Q waves or loss of R waves; if only transient ST-segment and T-wave changes are present, nontransmural MI may be indicated.

    Serum Cardiac Biomarkers

    • Cardiac biomarkers appear in peripheral blood when the cardiac lymphatics cannot clear the infarct zone interstitium, leading to a spillover into circulation.
    • Cardiac-specific troponin T (cTnT) and I (cTnI) may significantly increase after ST-Elevation Myocardial Infarction (STEMI), often exceeding the upper reference limit.

    Cardiac Imaging

    • 2D echocardiography typically shows abnormalities in wall motion, aiding in swift diagnosis.
    • The absence or presence of wall motion abnormalities detected via echocardiography informs management decisions regarding reperfusion therapy such as fibrinolysis or percutaneous coronary intervention (PCI).
    • Echocardiography can reveal right ventricular (RV) infarction, ventricular aneurysm, pericardial effusion, and left ventricular (LV) thrombus.
    • Doppler echocardiography assists in detecting and quantifying ventricular septal defects and mitral regurgitation—serious complications of STEMI.

    Other Imaging Techniques

    • Cardiac MRI, particularly late enhancement techniques, help in further evaluation of myocardial damage.
    • Radionuclide imaging techniques are also applicable for assessing cardiac conditions.

    Definitions of Key Terms in Cardiology

    • First Medical Contact (FMC): Refers to the initial assessment of a patient experiencing cardiac symptoms by qualified healthcare personnel (physician, paramedic, nurse, or EMS personnel) either in a prehospital setting or upon arrival at a hospital, such as the emergency department.

    • STEMI Diagnosis: Defined as the moment when a patient presenting with ischemic symptoms is identified as having ST-segment elevation on an ECG, indicating a serious heart condition.

    • Primary PCI (Percutaneous Coronary Intervention): An urgent procedure involving the use of a balloon, stent, or other approved devices to treat the infarct-related artery (IRA) without prior fibrinolytic therapy, aimed at restoring blood flow to the heart.

    • Rescue PCI: An emergency PCI performed as soon as possible when initial fibrinolytic treatment fails to restore adequate blood flow, providing a critical intervention to prevent further damage.

    • Pharmacoinvasive Strategy: A combined approach that utilizes fibrinolysis followed by either a rescue PCI in case of treatment failure or a routine early PCI strategy following a successful fibrinolysis, optimizing patient outcomes.

    Prognosis in Cardiac Events

    • Prognosis is influenced by two main types of complications: electrical (arrhythmias) and mechanical (pump failure).

    Prehospital Care

    • Effective prehospital care can impact overall patient outcomes, transitioning quickly to hospital management.

    Emergency Room Management

    • Main objective: Reduce the duration from first medical contact to beginning reperfusion therapy, maximizing patient recovery chances.
    • Patients may need to be transferred from non-PCI hospitals to PCI-capable facilities.

    Reperfusion Therapy Timing

    • Ideal initiation of Percutaneous Coronary Intervention (PCI) should occur within 120 minutes of first medical contact.
    • Fibrinolysis should be initiated within 30 minutes of patient presentation, with a target door-to-needle time of 90 minutes.

    Indicators for Urgent PCI

    • Consider urgent PCI if there's coronary artery reocclusion indicated by ST segment elevation or recurrent chest pain.
    • Development of recurrent ischemia, such as recurrent angina or a positive exercise stress test prior to discharge, is another indicator for urgent PCI consideration.

    Anti-thrombotics

    • Aspirin: Chewed 160-325 mg tablet for rapid Cox-1 inhibition, reducing thromboxane A2 levels. Followed by daily doses of 75-162 mg.
    • P2Y12 ADP Receptor Antagonists: Prasugrel and Ticagrelor show greater efficacy than Clopidogrel for ischemic complications in STEMI patients receiving PCI.
    • Unfractionated Heparin (UFH): Initial bolus of 60 U/kg (max 4000U) with infusion of 12 U/kg/h; APTT target is 1.5-2 times control value.
    • Enoxaparin (LMWH): High bioavailability allows subcutaneous administration, providing reliable anticoagulation without monitoring.
    • Fondaparinux: Demonstrated superiority over placebo in untreated STEMI patients; however, its safety compared to UFH is uncertain.

    Beta-Adrenoceptor Blockers

    • Improves myocardial oxygen supply-demand balance.
    • Reduces pain and infarct size.
    • Decreases incidence of serious ventricular arrhythmias.

    Inhibition of RAAS

    • ACE Inhibitors: Lower mortality rates after STEMI; greater benefits in high-risk groups (elderly, anterior infarction, previous infarction, depressed left ventricular function).
    • ARBs: Administered to STEMI patients intolerant to ACE inhibitors, especially those with heart failure signs.
    • Mineralocorticoid Receptor Antagonists (e.g., Spironolactone, Eplerenone): Used in STEMI patients with LVEF ≤40%, symptomatic heart failure or diabetes, and without significant renal dysfunction.

    Others

    • Activity: Recommend bed rest for 6-12 hours, followed by upright posture to reduce pulmonary capillary wedge pressure.
    • Diet: NPO for initial 4-12 hours; fat intake ≤30%, cholesterol ≤300 mg/d; complex carbohydrates should constitute 50-55% of intake.
    • Bowel Management: High-bulk diet and routine stool softeners like dioctyl sodium sulfosuccinate (200 mg/d) recommended.
    • Sedation: Agents like Diazepam (5 mg), Oxazepam (15-30 mg), or Lorazepam (0.5-2 mg) to assist with inactivity.
    • Nitroglycerin: Initial dose of 5-10 mcg/min, with a maximum of 200 mcg/min while maintaining hemodynamic stability for the first 24-48 hours.
    • Calcium Channel Blockers (CCB): No role in treating STEMI patients.

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    Test your knowledge on Acute Coronary Syndrome, focusing on Non-ST-Elevation Myocardial Infarction (NSTEMI) and unstable angina. Explore the pathophysiology and causes of ACS, including the critical concepts of myocardial oxygen supply and demand balance.

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