Understanding Atrial Fibrillation
Atrial fibrillation (AFib) is the most common sustained cardiac arrhythmia. Recognition on ECG is essential for emergency medicine and cardiology practice.
Classic ECG Features
Primary Findings
-
Irregularly Irregular Rhythm
- No discernible pattern to R-R intervals
- Most distinctive feature
-
Absent P Waves
- Replaced by fibrillatory waves
- Variable morphology
-
Narrow QRS Complex
- Unless aberrant conduction present
- Rate typically 120-160 bpm (uncontrolled)
Rate Classification
- Slow AFib: < 60 bpm
- Controlled AFib: 60-100 bpm
- RVR (Rapid Ventricular Response): > 100 bpm
Clinical Management
Rate vs Rhythm Control
Rate Control Options:
- Beta-blockers (Metoprolol)
- Calcium channel blockers (Diltiazem)
- Digoxin
Rhythm Control:
- Cardioversion (chemical or electrical)
- Antiarrhythmic drugs
Anticoagulation
CHA2DS2-VASc Score for stroke risk:
- Use our CHA2DS2-VASc Calculator
AFib with RVR
Rapid ventricular response requires urgent treatment:
- Assess hemodynamic stability
- Consider synchronized cardioversion if unstable
- Rate control medications if stable
Conclusion
Recognizing atrial fibrillation on ECG is crucial for appropriate management and stroke prevention. Always assess rate, rhythm, and clinical stability.
