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: Normal T Wave in V1: The normal ECG typically shows a flat or inverted T wave in lead V1 in sinus rhythm. An upright T wave in V1 can…
Key Points PACs are early atrial depolarizations from an ectopic focus that create a premature P wave with a different morphology and axis than the sinus P wave, usually followed…
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 PJCs are premature impulses from ectopic foci in or near the AV junction. ECG hallmark is a narrow premature beat with an absent or retrograde P wave. Retrograde…
Key Points The J point is the junction where QRS ends and the ST segment begins. It is a location, not a waveform. ST deviation is judged at the J…
Key Points Definitions: The J point is the QRS–ST junction (a location). A J wave is an added deflection at or just after that point (notch or slur). Why it…