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: 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: Sudden failure of AV conduction after at least two consecutive conducted beats with identical PR intervals, followed by a single non‑conducted P wave. Sinus rate: P–P interval…
Key Points ECG as a Critical Diagnostic Tool: In toxicology, the ECG is often the first and most reliable clue. Early recognition of drug-induced conduction disturbances or arrhythmias can guide…
Key Points: What it is: In V2 or V3, there is no S wave (the R does not descend below the PQ baseline) and no J wave (no notch/slur at…
Key Points Narrow therapeutic window: Small dosing errors or renal decline can push serum digoxin above the safe range. Excess automaticity + AV block: Toxicity increases atrial and ventricular irritability…
Key Points RAD combined with ST-segment elevation (STE) is an uncommon but high-risk finding. While STE often suggests acute coronary occlusion, this pattern rarely reflects classic STEMI. Several non-ischemic conditions…
Key Points Do not fully trust computer interpretations of “normal” ECGs, they may miss significant abnormalities. Computer algorithms can miss early ischemic signs such as reciprocal changes in aVL and…
Key Points Definition: Pseudonormalization is the apparent normalization of previously inverted T waves, often signaling reocclusion of a coronary artery that had recently reperfused. Mechanism: During reperfusion, ischemic T wave…
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 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 Definition: Trifascicular block describes ECG evidence of impaired conduction across all three fascicles: right bundle branch (RBB), left anterior fascicle (LAF), and left posterior fascicle (LPF). Common Usage:…
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 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…