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 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 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 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 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…
Key Points: Life-Threatening Sodium Channelopathy: Predisposes to ventricular arrhythmias (VF/VT) and sudden cardiac death (SCD), often in otherwise “healthy” hearts. When to Suspect BrS: Patients with syncope, unexplained “seizures,” ventricular…
Key Points Definition: A rare ion channelopathy that causes sudden, reversible episodes of symmetric flaccid paralysis triggered by low serum potassium. It may be inherited or secondary to thyrotoxicosis or…
Key Points Prolonged QT & PR Intervals significantly increase the risk of torsades de pointes and other arrhythmias. Atrial & Ventricular Ectopy is common; can progress to life-threatening ventricular tachycardia….
Key Points Definition & Terminology: Arrhythmogenic Cardiomyopathy (ACM), previously known as Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia (ARVC/D), is an inherited disorder characterized by progressive fibrofatty replacement of the ventricular myocardium, predominantly…