Final answer:
Atrial fibrillation is an irregular rhythm characterized by continuous chaotic atrial spikes, rapid firing of multiple atrial foci, and no visible P wave. It is a common type of arrhythmia.
Step-by-step explanation:
An irregular rhythm characterized by continuous chaotic atrial spikes, continuous rapid firing of multiple atrial foci, and no visible P wave is known as atrial fibrillation. In atrial fibrillation, not all atrial contractions conduct to the ventricles, leading to an irregular heartbeat. Atrial fibrillation is a common type of arrhythmia that is due to problems with the electrical conduction system of the heart.