Key Points: The ECG’s primary role in ACS is detecting acute coronary occlusion. Acute coronary occlusion myocardial infarction (OMI) is a time-critical diagnosis that requires immediate reperfusion. Time is myocardium….
Key Points: Prolonged QTc is the hallmark ECG change in hypocalcemia, driven mainly by ST-segment prolongation with relatively normal T-wave shape. Hypocalcemia can increase arrhythmia risk, including TdP, but TdP…
Key Points: Shortened QTc interval is the hallmark ECG clue in hypercalcemia, primarily due to a shortened ST segment duration. Hypercalcemia can mimic acute STEMI on ECG (pseudoinfarction pattern due…
Key Points: Definition: A true LV aneurysm is a chronic, post transmural MI complication from scarred myocardium with akinetic or dyskinetic (paradoxical) wall motion. ECG hallmark: Persistent ST elevation in…
Key Points: Acute pericarditis commonly mimics ACS clinically and on ECG, creating frequent diagnostic uncertainty in acute care. The first priority is excluding occlusion MI. Pericarditis should be considered only…
Key Points: ECG as a Frontline Diagnostic Tool: Hyperkalemia often reveals itself on the ECG before lab confirmation. Early recognition of characteristic changes can be life-saving, especially in critically ill…
Key Points: Severe Hyperkalemia Mimics Several Life-Threatening Conditions: Severe hyperkalemia is one of the most dangerous ECG mimics in emergency medicine. It can resemble unstable bradyarrhythmias, VT, STEMI, and pacemaker…
Key Points: Historical View: Early repolarization (ER) was long considered a benign cause of ST elevation, often called benign early repolarization (BER). Modern View: Certain ER patterns, now termed malignant…
Key Points: WPW alters ventricular depolarization, producing secondary repolarization abnormalities that can mimic or mask myocardial infarction. ST-segment deviation in WPW is often non-ischemic, driven by abnormal activation via the…
Key Points Reperfusion after fibrinolysis is a bedside diagnosis using a bundle of findings: symptoms, ECG trend, and hemodynamic/electrical stability. Best ECG marker of successful fibrinolysis: at least 50% ST-segment…
Key Points Reperfusion and re-occlusion can occur spontaneously or after therapy. The ECG often reflects these changes earlier than symptoms. Most useful bedside ECG marker of reperfusion is ST-segment resolution…
Key Points STEMI criteria alone miss some acute coronary occlusions, so look for subtle “occlusion clues,” not just traditional STEMI criteria cutoffs. Minor ST elevation under 1 mm paired with…
Key Points ACS is a clinical syndrome: classified by ischemic symptoms + ECG + troponin. ACS exists on a continuum of unstable angina, NSTEMI, STEMI, and patients can evolve between…
Key Points: Mechanical artifact caused by an ECG electrode sitting on top of a strong arterial pulse. Seen frequently in dialysis patients with AV fistulas. Can mimic serious pathology including…
Key Points STEMI Equivalent: The de Winter ECG pattern is an uncommon STEMI equivalent indicative of an unstable proximal occlusion of the LAD (left anterior descending coronary artery). Treat the…
Key Points Pacemaker syndrome is a hemodynamic problem caused by loss of proper atrioventricular (AV) synchrony. Most commonly occurs with ventricular pacing that produces retrograde atrial activation, but can also…
Key Points Pacemakers treat bradyarrhythmias by delivering timed atrial, ventricular, or dual-chamber pacing when intrinsic activity is slow or absent. Know the major device types encountered in the ED: single-chamber,…
Key Points Ventricular pacing changes depolarization, so ST–T segments often look “abnormal.” Expect appropriate discordance: ST/T deflect opposite the main QRS polarity. RV pacing (most common) ≈ LBBB pattern: wide…
Key Points Tall, broad-based T–U fusion that looks like a mountain peak, usually from severe hypokalemia; think high torsades risk until proven otherwise. Hallmark is prolonged repolarization: QT appears long…
Key Points Pediatric ECGs are not scaled-down adult ECGs. Right axis deviation, large R waves in V1, and T wave inversions in V1 to V3 are expected in healthy children….
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