Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
Fibrillation is the rapid, irregular, and unsynchronized contraction of muscle fibers, particularly evident in the heart muscles. This can significantly disrupt the normal rhythm of the heart, leading to decreased blood flow.
Related terms
Arrhythmia: An arrhythmia is any disorder of the heart rate or rhythm, where the heart beats too fast, too slow, or with an irregular pattern.
An electrocardiogram is a medical test that records the electrical activity of the heart and is used to diagnose various cardiac conditions including fibrillation.
Cardiac Arrest: Cardiac arrest is a sudden loss of blood flow resulting from the failure of the heart to effectively pump; fibrillation can be a common cause