Overview

• Tachyarrhythmia at the rapid end of flutter/fibrillation spectrum
• Produced by macro-reentry within multiple circuits in atria; characterized by irregular multiform f waves

ECG Features

• Indiscernible, absent P waves with an irregularly irregular ventricular rate
• Atrial activity is represented by fibrillatory (“f”) waves with no organized pattern
• Classification based on ventricular rate: <60 beats/min = slow ventricular rate (SVR), 60-100 beats/min = controlled ventricular rate (CVR), >100 beats/min = rapid ventricular rate (RVR)