Key Points Definition: Right atrial enlargement (RAE) is an increase in the size of the right atrium, typically resulting from chronic pressure or volume overload, commonly related to cardiac or…
Key Points Short QT Syndrome (SQTS) is a rare condition characterized by a shortened QT interval on the ECG, increasing the risk of atrial and ventricular arrhythmias, including sudden cardiac…
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 Definition: SA exit block occurs when the sinus node generates impulses that are blocked before they can activate the right atrium, leading to dropped P waves on the…
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 Definition: Unifascicular block refers to conduction delay or interruption in a single fascicle of the ventricular conduction system: the right bundle branch (RBB), left anterior fascicle (LAF), or…
Key Points ECG Findings in PE: No single ECG pattern is diagnostic of acute PE, and ECG findings are typically nonspecific. However, certain ECG patterns, especially those indicating right heart…
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 Definition: QRS voltage represents the amplitude (height) of the QRS complex on ECG, reflecting ventricular electrical activity during depolarization. High Voltage: Increased QRS voltage typically indicates ventricular hypertrophy—most…
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: Electrocardiography Defined: An ECG records the heart’s electrical activity in real time, offering a rapid window into rate, rhythm and conduction. The ECG measures changes in voltage between…
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 Point Always consider pericardial effusion in any patient with new low-voltage QRS complexes combined with sinus tachycardia. Prompt bedside ultrasound (POCUS) prevents diagnostic delays and potentially catastrophic outcomes. Classic…
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…