Key Points Tall, broad-based T–U fusion that looks like a mountain peak, usually from severe hypokalemia; think high torsades risk until proven otherwise. Hallmark is prolonged repolarization: QT appears long…
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 ECG rhythms in pediatric arrest differ from adults. Pulseless arrest in children is most often asphyxial, but ECG clues can reveal reversible metabolic, toxicologic, or structural causes. Wide…
Key Points: Pseudo-Wellens waves are anterior T-wave patterns that mimic the biphasic or deeply inverted T waves of true Wellens syndrome but are caused by non-LAD, non-ischemic physiology. These normal-variant…
Key Points Wellens waves are anterior precordial T wave abnormalities (biphasic or deeply inverted) most often in V2–V3, occasionally extending to V1 and V4–V6. They signal a high likelihood of…
Key Points: Clinical diagnosis, not an ECG pattern alone. Wellens syndrome requires the characteristic ECG findings plus the appropriate clinical scenario. Morphology alone is insufficient and high-risk if misapplied. Critical…
Key Points Definition: TdP is a specific subtype of polymorphic ventricular tachycardia associated with a prolonged QTc interval. It often presents with a “twisting” pattern on ECG but can be…
Key Points VT is a ventricular-origin rhythm: ≥3 consecutive ventricular beats, QRS >120 ms, rate usually 120–250 bpm. Types include monomorphic VT, polymorphic VT, torsades (PMVT with long QT), ventricular…
Key Points: Initial Assumption: Any wide (QRS >120 ms), regular tachycardia should be considered ventricular tachycardia (VT) until clearly proven otherwise. VT Characteristics: VT generally has a ventricular rate of…
Key Points Defibrillation First, Minimal Pauses: pVT is rapidly fatal without immediate shocks and high‑quality CPR. Charge defibrillator during compressions and resume compressions immediately after each shock. pVT is a…
Key Points: High-risk STEMI morphology caused by fusion of the terminal QRS, J point, ST segment, and T wave into a single “triangular” deflection. Often massive apparent STE with loss…
Key Points Definition: Electrical storm is defined as three or more episodes of sustained ventricular tachycardia (VT), ventricular fibrillation (VF), or appropriate implantable cardioverter-defibrillator (ICD) shocks within 24 hours. Some…
Key Points Definition: Organized electrical activity on ECG without a palpable pulse. PEA is a non-shockable arrest rhythm requiring CPR, epinephrine, and identification of reversible causes. Confirmation: Verify in two…
Key Points Definition: Asystole is a non-shockable cardiac arrest rhythm characterized by absence of ventricular electrical activity. Treat with high-quality CPR, epinephrine every 3–5 minutes, and an urgent search for…
Key Points Defibrillation First, Minimal Pauses: VF is rapidly fatal without immediate shocks and high‑quality CPR. Charge during compressions and resume compressions immediately after each shock. Chaotic Electrical Activity: VF…
Key Points Definition: A malignant ventricular tachyarrhythmia with a regular, sine-wave–like waveform at ~250–350 bpm, no isoelectric baseline, and no discernible P/QRS/T distinction. Clinical importance: Rapidly degenerates into ventricular fibrillation…
Key Points Early post-ROSC ECGs often mislead. Within the first 8–10 minutes, transient global ischemia and catecholamines can exaggerate ST changes. Plan a repeat at 10–15 minutes before making cath…
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…
Key Points: Intervene Immediately: Unstable tachyarrhythmias pose significant risk for rapid clinical deterioration that may lead to irreversible end-organ damage or cardiac arrest. Clinical Indicators of Instability: Altered Mental Status:…
Key Points Severe hypothermia causes rate- and temperature-dependent ECG changes that signal high arrhythmia risk. Recognition guides safe rewarming and prevents iatrogenic VF. Osborn (J) waves may appear and typically…