Key Points 1. Paced Rhythms and Acute MI Detection: Ventricular paced rhythms significantly alter ST segment and T wave morphology, complicating acute myocardial infarction (MI) recognition. Accurate ECG interpretation in…
Key Points LBBB Does Not Exclude Acute Coronary Occlusion: LBBB alters ventricular activation, leading to expected secondary ST/T abnormalities. However, acute occlusion myocardial infarction (OMI) can and must still be…
Key Points Wide QRS Rhythms Can Mask OMI: Left bundle branch block (LBBB) and right ventricular (RV)-paced rhythms alter ventricular depolarization, producing expected secondary ST/T changes. However, acute occlusion MI…
Key Points What It Is: A rare autosomal dominant sodium channelopathy that leads to episodic muscle weakness or paralysis in the setting of elevated serum potassium. Named after “Impressive,” the…
Key Points Spectrum, not one rhythm: Look for sinus brady, pauses, arrest, alternating atrial tachyarrhythmias (AF, flutter, ATach). Symptoms matter: Syncope, presyncope, fatigue usually come from cerebral/systemic hypoperfusion, especially after…
Key Points Definition: Atrial fibrillation with a slow ventricular response, usually < 60 bpm. ECG: Irregularly irregular rhythm, no discrete P waves, slow R-R intervals. Common causes: AV-nodal blockers (digoxin,…
Key Points: STEMI Diagnosis and Contiguous Leads: While current guidelines typically require ST elevation (STE) in at least two contiguous leads for the diagnosis of STEMI, this practice is not…
Key Points Definition: The precordial swirl sign refers to a rotational pattern of ST-segment abnormalities across the precordial leads, suggesting a dynamic and evolving occlusion myocardial infarction (OMI). It is…
Key Points Pattern: ST elevation in aVR (≥1 mm), often with ST elevation in V1 and widespread ST depression (≥1 mm in ≥6 leads). Mechanism: Reflects global subendocardial ischemia, often…
Key Points Beyond Electrical Alternans: Although classically linked to tamponade, electrical alternans is present in fewer than 30% of confirmed cases. It’s abscence should never rule out tamponade. Low Voltage…
Key Points Classically associated with pericardial tamponade but seen in fewer than 30% of confirmed cases. Combination of low-voltage QRS + sinus tachycardia strongly suggests pericardial effusion/tamponade. Always perform rapid…
Key Points Definition: PMVT is a ventricular tachycardia characterized by beat-to-beat variations in QRS morphology, axis, and duration, reflecting multiple ventricular foci or reentrant circuits. Clinical Importance: PMVT is often…
Key Points High Risk of Missed Diagnosis: Isolated posterior occlusion MI is frequently missed due to the absence of ST elevation on standard 12-lead ECG. Instead, ST depression in V1–V3…
Key Points Most Missed STEMI: Isolated posterior MI is the most commonly missed occlusion MI due to the absence of ST elevation on standard 12-lead ECG. ECG Pattern of Posterior…
Key Points Recognizing the Danger: Sodium channel blocker toxicity can present with a variety of ECG changes that are critical to recognize, especially in patients with altered mental status or…
Key Points Definition: NSVT is defined as ≥3 consecutive ventricular beats, QRS duration >120 ms, rate typically 100-250 bpm (usually > 120 bpm), lasting less than 30 seconds without causing…
Key Points for EMS Providers: You are the first critical link in the chain of survival for ACS patients—your actions set the course for their care, directly impacting time to…
Key Points: WPW Syndrome: A condition characterized by ventricular pre-excitation due to a congenital accessory pathway, often associated with symptomatic arrhythmias. ECG Recognition: The WPW pattern is best identified when…
Key Points ACS Dynamics: Occluded arteries in ACS can spontaneously reperfuse and reocclude, making ECG findings variable. Limitations of Computer Interpretation: Subtle STE is often missed by computerized ECG interpretation;…
Key Points Pattern Recognition: The South African Flag Sign is characterized by: ST-segment elevation (STE) in leads I, aVL, and V2. ST-segment depression in lead III. Subtle but visually distinctive…
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