Which EKG finding is characteristic of atrial fibrillation?

Which EKG finding is characteristic of atrial fibrillation?

• A. Irregularly irregular rhythm with no discrete P waves.
• B. Regular rhythm with clear P waves
• C. Sawtooth pattern of atrial activity
• D. Prolonged QRS duration with consistent P waves

Answer: (A)

Atrial fibrillation shows disorganized atrial activity that leads to an irregularly irregular rhythm, because the AV node conducts impulses to the ventricles in an unpredictable way. The atria do not depolarize in a coordinated, uniform manner, so discrete P waves are absent on the ECG; instead you may see a jagged, chaotic baseline or fibrillatory waves. This combination—no distinct P waves with an irregular R-R interval—is the hallmark that sets AF apart from other rhythms. By contrast, a regular rhythm with clear P waves points to organized atrial activity such as sinus rhythm, a sawtooth atrial pattern describes atrial flutter, and a prolonged QRS with consistent P waves suggests a conduction or pacing issue rather than AF.

Atrial fibrillation shows disorganized atrial activity that leads to an irregularly irregular rhythm, because the AV node conducts impulses to the ventricles in an unpredictable way. The atria do not depolarize in a coordinated, uniform manner, so discrete P waves are absent on the ECG; instead you may see a jagged, chaotic baseline or fibrillatory waves. This combination—no distinct P waves with an irregular R-R interval—is the hallmark that sets AF apart from other rhythms. By contrast, a regular rhythm with clear P waves points to organized atrial activity such as sinus rhythm, a sawtooth atrial pattern describes atrial flutter, and a prolonged QRS with consistent P waves suggests a conduction or pacing issue rather than AF.