Atrial Fibrillation ECG Features: Complete Recognition Guide

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

1. Irregularly Irregular Rhythm

   • No discernible pattern to R-R intervals
   • Most distinctive feature

2. Absent P Waves

   • Replaced by fibrillatory waves
   • Variable morphology

3. 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:

1. Assess hemodynamic stability
2. Consider synchronized cardioversion if unstable
3. 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.