Key Points: Stable post-arrest patients without ST elevation should not go to reflex immediate cath solely because cardiac arrest occurred. Randomized trials in OHCA patients without ST elevation have not…
Key Points: Pediatric arrest is usually respiratory, hypoxic, or shock-related, not primary coronary occlusion. The ECG still matters because it can reveal reversible metabolic, toxicologic, structural, inflammatory, or inherited electrical…
A 72-year-old man is brought to the ED after a witnessed out-of-hospital cardiac arrest. Bystander CPR is started quickly, EMS finds a non-shockable rhythm, and ROSC is achieved after one…
A 70-year-old woman with CHF, COPD, intermittent atrial fibrillation, chronic pain medication use, and recent poor intake develops sudden dyspnea at rest and is found somnolent and bradycardic in the…
Key Points: A spectrum, not a single rhythm: Sinus node dysfunction includes inappropriate sinus bradycardia, sinus pauses or arrest, SA exit block, chronotropic incompetence, and alternating atrial tachyarrhythmias with bradycardia….
Key Points: Definition: Sinoatrial, or SA, exit block occurs when the sinus node generates an impulse that fails to conduct into the surrounding atrial tissue. The blocked impulse produces no…
Key Points: Definition: Sinus arrest occurs when the sinus node temporarily fails to generate an impulse. This produces an absence of the expected P wave and its associated QRS complex….
A 44-year-old man with severe cardiomyopathy, an LVAD, chronic amiodarone therapy, and an AICD presents with palpitations. His ECG shows a regular wide-complex tachycardia, but the rate is only 135….
Key Points: In a patient with ischemic symptoms, new RBBB + LAFB should raise concern for proximal LAD or septal ischemia until proven otherwise, especially if the patient has ongoing…
Key Points: A QRS duration greater than 120 ms reflects delayed or abnormal ventricular depolarization. A wide QRS may be chronic and benign in context, or it may be the…
A 71-year-old man presents with shortness of breath, and his ECG is initially read as a junctional rhythm. On later review, it is even mistaken for atrial fibrillation. But the…
Key Points: Continuous-flow LVADs can mask cardiovascular collapse. Patients may remain awake during sustained VT or even VF because the pump can provide temporary flow. Treat the rhythm and the…
Key Points: Any wide QRS (>90 ms) in an infant or small child is abnormal and should trigger evaluation for VT, sodium-channel blockade, or conduction disease. QTc >450 ms in…
Key Points: Unstable bradyarrhythmias cause poor perfusion which can rapidly progress to shock, irreversible organ injury, or cardiac arrest. Priority: Do not treat the heart rate alone. Treat clinical instability….
Key Points: Severe hypothermia causes predictable ECG slowing and conduction delay. Sinus bradycardia, PR/QRS/QT prolongation, and atrial fibrillation with a slow ventricular response are common as core temperature falls. Osborn…
An 81-year-old woman presents with lightheadedness and marked bradycardia. Her ECG shows more P waves than QRS complexes, but the mechanism is not immediately clear. The key question is whether…
Key Points: Do not trust a computer read of “normal” without your own review. Computer interpretation is especially unreliable for subtle or early ischemia, including hyperacute T waves, minimal ST…
Key Points: Definition: Torsade de pointes is a specific subtype of polymorphic ventricular tachycardia that occurs in the setting of QT prolongation. ECG pattern: TdP shows beat-to-beat variation in QRS…
Key Points: Pattern, not a STEMI equivalent. ST elevation in aVR (≥1 mm), often with ST elevation in V1 and diffuse ST depression (≥1 mm in ≥6 leads), represents high-risk…
Key Points: Severe Hyperkalemia Mimics Several Life-Threatening Conditions: Severe hyperkalemia is one of the most dangerous ECG mimics in emergency medicine. It can resemble unstable bradyarrhythmias, VT, STEMI, and pacemaker…