Key Points: Not all ST elevation is ischemia. The most common mimics at the point of care are atrial activity riding on the ST segment, motion or lead artifact, early…
Key Points ECG alone cannot reliably distinguish VT from SVT-aberrancy in many cases. Use ECG features to rule in VT, not to exclude it. Default: treat regular WCT as VT…
Key Points Idiopathic monomorphic VT arising from the right ventricular outflow tract. Most patients have no structural heart disease; catecholamine and cAMP-mediated triggers are common. Classic ECG pattern: LBBB morphology…
Key Points: Hypokalemia slows ventricular repolarization and alters the T–U complex before it triggers arrhythmias. Progressive pattern: T-wave flattening → prominent U waves → T–U fusion with apparent QT prolongation;…
Key Points Severe hypokalemia can produce dramatic ECG changes that may be mistaken for acute coronary syndromes. It can also precipitate life-threatening arrhythmias, including torsades de pointes and ventricular tachyarrhythmias…
Key Points Artifacts = non-cardiac signals that distort or obscure true ECG. They come from the patient, leads/equipment, or the environment. Clues to artifact: lacks a physiologic pattern, varies beat-to-beat…
Key Points Idiopathic reentrant VT arising within the left Purkinje system, most often the left posterior fascicle. Patients are usually young and lack structural heart disease. Signature ECG: RBBB-like morphology…
Key Point Opioid overdose causes life-threatening respiratory depression leading to hypoxia, altered mental status, bradycardia, hypotension, and potentially death. While most cardiovascular effects are secondary to hypoxia, methadone toxicity uniquely…
Key Point Methamphetamine is a powerful sympathomimetic that causes a massive catecholamine surge, it can result in life-threatening cardiovascular and neurologic complications. Toxicity can present with MI, arrhythmias, stroke, hypertensive…
Key Point BBs and CCBs are widely prescribed but overdoses can cause life-threatening bradycardia, AV block, hypotension, and shock. Differentiating between them is important, but both require early recognition, aggressive…
Key Point Cocaine is a powerful sympathomimetic with profound cardiovascular (CV) effects. Even recreational or first-time use can precipitate life-threatening complications, including myocardial infarction (MI), stroke, arrhythmias, and aortic dissection….
Key Points Definition: A type of AV dissociation in which sinus and escape rates are nearly identical, so P waves and QRS complexes appear to “track” each other while remaining unrelated….
Key Points: Definition: Third-degree AV block is complete failure of conduction from atria to ventricles, resulting in independent atrial and ventricular activity—known as AV dissociation. Hallmark Feature: No P waves…
Key Points Definition: A severe form of second-degree AV block with two or more consecutive non‑conducted P waves (for example 3:1, 4:1). Do not force a Mobitz label when multiple…
Key Points Definition: Slow ventricular tachycardia is defined as a wide complex tachycardia with a ventricular rate between 100–120 bpm. Distinction: Typical sustained VT usually exceeds 120 bpm. When encountering…
Key Points Definition: Sinus pause/arrest is failure of the sinus node to generate an impulse, producing a transient absence of P waves. On ECG the pause does not equal an…
Key Points Definition: The R on T phenomenon occurs when an ectopic impulse (often a PVC or cardioversion shock) falls on the T wave of the preceding beat. Mechanism: Interrupting…
Key Points RV involvement accompanies up to ~40% of inferior STEMIs; isolated RV infarction is uncommon but high-impact when missed. Think RV MI when inferior STEMI is present and you…
Key Points: Definition: Progressive PR interval prolongation until one atrial impulse fails to conduct to the ventricles (P wave is non-conducted), after which the cycle repeats. Site of Block: Typically…
Key Points: Definition: A form of second-degree AV block in which every other atrial impulse is blocked, producing a 2:1 atrioventricular conduction ratio. Typing Limitation: Differentiating between Mobitz I and…