Key Points:
- A differential diagnosis is the structured process of considering multiple possible conditions that could explain a patient’s symptoms and ECG findings. This hub is a curated index of ECG centered differentials listed by acuity for rapid bedside reference.
- What "DDx" Means Here: When you identify an abnormal ECG finding (wide QRS, diffuse ST elevation, no P waves, etc.), this hub gives you a focused list of the most important causes so you do not anchor on the first explanation.
- STAT findings are the priority: In acute care, where history and exam may be limited, ECG-based DDx lists help identify critical conditions early. Start with life-threatening diagnoses first, then work down to common and benign mimics.
- Practical Use: When you identify an ECG abnormality, anchor your thinking with a focused list of the most important and life-threatening differentials before moving to less urgent possibilities.
How to Use This Hub:
- Name the ECG abnormality (not the diagnosis): “wide and regular tachycardia,” “diffuse ST elevation,” “prolonged QT.”
- Open the relevant DDx post below.
- Rule out killers first using the clinical story, vitals, and a targeted bedside workup.
- Reassess with new data (serial ECGs, electrolytes, troponin trend, echo, imaging). Your differential should evolve.
Quick rule: If your interpretation cannot confidently explain the ECG abnormalities in critical patients, treat it as high-risk until proven otherwise.
Search or browse the Must-Know DDx Collection here:
Key Clinical Pearls:
- Always consider the worst case scenario first. For any abnormal ECG finding, your first pass should explicitly consider acute coronary occlusion, malignant arrhythmia, hyperkalemia/toxicity, high-risk PE, tamponade, and aortic catastrophe when clinically plausible.
- Use a structured method. A consistent workflow prevents “pattern shopping” and reduces missed killers. Review the STAT ECG 101: Workflow post below to help with this.
- Serial ECGs are a diagnostic tool. Dynamic change can confirm evolving ischemia, reperfusion, toxicity progression, or conduction deterioration. When in doubt, simply repeat an ECG.
- Avoid single-lead thinking. Territorial coherence, reciprocal changes, QRS morphology, and comparison to prior tracings are often more informative than one single measurement.
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