Atrial flutter is a health condition (arrhythmia) where the atria of the heart as an electrical problem (a re-entry loop) that causes the atria to beat at a rapid rate of about 242 - 360 beats per minute (bpm). It is the second most common tachyarrhythmia, with atrial fibrillation (AFib) being the most common. Although usually flutter waves are regular and appear as "sawtooth" P waves in ECG's (typical atrial flutter); occasionally electrical conduction blocks can occur and produce 2:1, 3:1 or 4:1 waves or even appear as irregular bpm's resembling an irregular arrhythmia. Infrequently, atrial flutter may be seen with bradycardia (an abnormal heart rhythm that is slow) when the heart ventricles do not receive most of the atrial flutter P waves and thus do not mimic the atrial rate.