A rapid heart rate due to more than one pathway through the AV node. Many impulses begin and spread through the atria, competing for a chance to travel through the AV node. The resulting rhythm is disorganized, rapid and irregular. Because the impulses are traveling through the atria in a disorderly fashion, it results in loss of coordinated atrial contraction. An atrial arrhythmia caused by one or more rapid circuits in the atrium.
Atrial flutter is usually more organized and regular than atrial fibrillation.
PVCs are common. Most of the time they cause no symptoms and require no treatment. In some people, they can be related to stress, too much caffeine or nicotine, or exercise. But sometimes, PVCs can be caused by heart disease or electrolyte imbalance. The rapid rate prevents the heart from filling adequately with blood, and less blood is able to pump through the body.