fibrillation
A rapid, uncoordinated series of contractions of some part of the heart muscle causing irregular heartbeats. Atrial fibrillation is the rapid, ineffective beating of the upper part of the heart. Ventricular fibrillation is the lethal rapid, ineffective beating of the lower part of the heart.
Last Updated
October 7, 2025
October 7, 2025
Last updated: October 7, 2025.
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