Atrial fibrillation with rapid ventricular response (Afib RVR) is a common cardiac arrhythmia characterized by irregular atrial activity and a fast ventricular rate. Identifying Afib RVR on an ECG involves recognizing the absence of P waves, irregularly irregular R-R intervals, and a ventricular rate typically greater than 100 bpm. Careful analysis of the ECG can help clinicians promptly diagnose and manage this condition.