ACUTE CORONARY SYNDROMES (ACS)Initial EvaluationAssess Symptoms: Obtain history of substernal or left-sided chest discomfort, pain, or pressure, potentially radiating to the left arm, neck, or jaw. Inquire about accompanying dyspnea, nausea, vomiting, diaphoresis, lightheadedness, or palpitations. Consider Atypical Presentations: Be vigilant for atypical symptoms or "silent MI," particularly in women, older individuals, and patients with diabetes.Perform Focused Physical Examination:Vascular Assessment: Check for signs of extracardiac atherosclerosis (carotid or peripheral bruits).Cardiac & Hemodynamic Status: Auscultate for an S4 (impaired LV compliance) or S3, and rales, jugular venous distension, or edema (signs of heart failure). Note hypertension (due to adrenergic stimulation) or hypotension.Mechanical Complications: If hypotensive, actively look for new murmurs of mitral regurgitation (MR) or a ventricular septal defect (VSD), often with a palpable thrill.Right Ventricular (RV) Infarct: Suspect RV infarct if there is elevated jugular venous pressure (JVP), clear lung fields, and hypotension.Order Immediate Diagnostic Tests:12-Lead EKG: Obtain immediately to differentiate between NSTE-ACS and STEMI (or equivalent entities). If STEMI (or equivalent): Look for acute ST-segment elevations: ≥2 mm in men or ≥1.5 mm in women in leads V2–V3, or ≥1 mm in other leads in two contiguous leads. A new Left Bundle Branch Block (LBBB) is considered a STEMI equivalent. Consider an old LBBB with new ST deviations ≥1 mm concordant or ≥5 mm discordant as equivalent.If NSTE-ACS: Evaluate for ST-segment depressions, T-wave inversions or flattening, or nonspecific ST- and T-wave changes. Note dynamic EKG changes that correlate with chest discomfort, which are highly suggestive of ischemia.Cardiac Biomarkers: Order cardiac-specific troponins T and I immediately; these are the preferred biomarkers for diagnosing MI. Consider serial CK-MB levels for detecting reinfarction after initial MI, as they normalize more quickly.Initiate Continuous EKG Monitoring: Place the patient on continuous EKG monitoring to screen for ischemia and rhythm changes.Emergent ActionsBed Rest: Enforce immediate bed rest to reduce myocardial oxygen demand.Supplemental Oxygen: Administer supplemental oxygen if the oxygen saturation is <90%.Sedation/Anxiolytics: Consider sedation to decrease anxiety and catecholaminergic stimulation. Morphine may be used for refractory chest discomfort or in the presence of heart failure.Reperfusion Therapy for STEMI (or equivalent): This is critical for myocardial salvage and improved survival. If at a PCI-Capable Hospital: Perform Percutaneous Coronary Intervention (PCI) within 90 minutes of first medical contact.If Transferring to a PCI-Capable Hospital: Aim for PCI initiation within 120 minutes of first medical contact.If PCI Cannot Be Initiated within 120 Minutes AND <12 Hours Since Symptom Onset: Administer fibrinolysis within 30 minutes of first medical contact unless contraindicated. Absolute Contraindications to Fibrinolysis: Prior intracranial hemorrhage (ICH), intracranial neoplasm or AVM, ischemic CVA within the last 3 months (except ischemic stroke in the last 4.5 hours), suspected aortic dissection, active internal bleed (except menses), significant closed-head or facial trauma in last 3 months, intracranial or intraspinal surgery in last 2 months, severe uncontrolled hypertension refractory to therapy.Consider PCI regardless of time from symptom onset in the setting of heart failure or cardiogenic shock.If Ongoing Ischemia After Fibrinolysis: Proceed with rescue PCI.Diagnostics (Beyond Initial EKG and Biomarkers)Coronary Angiography (Cardiac Catheterization): This is the gold standard for defining severity and extent of coronary artery disease and is central to invasive management strategies. For NSTE-ACS, Risk Stratify for Timing of Angiography:Very High Risk (Immediate Invasive Strategy: within 2 hours): Patients with refractory angina, signs of heart failure, life-threatening ventricular arrhythmias (e.g., sustained VT/VF), or a high GRACE risk score.Intermediate-to-High Risk (Early Invasive Strategy: within 24 hours): Patients with an elevated GRACE risk score (>140), dynamic EKG changes, elevated cardiac biomarkers, recurrent ischemia or angina, EF <40%, hemodynamic or arrhythmic instability, pulmonary edema, diabetes, or renal insufficiency.Intermediate Risk (Delayed Invasive Approach: within 24-72 hours): Patients with an intermediate TIMI or GRACE risk score, diabetes, renal insufficiency, or LV dysfunction.Low Risk (Conservative/Ischemia-Guided Strategy): Patients who are troponin-negative with no high-risk clinical features. These patients should undergo a pre-discharge stress test. Angiography is reserved for those who fail medical therapy or demonstrate objective evidence of recurrent ischemia.Echocardiography: Useful for assessing cardiac structure and function, valve ...
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2025/06/2422 分