fibrillate

Fibrillate is a verb with several related meanings in biology and medicine. It denotes the act of causing or undergoing fibrillation—the rapid, unsynchronized contraction of muscle fibers or nerve fibers that produces a fine, twitching or quivering movement rather than a coordinated contraction. The term is used in both normal physiology and pathology.

In medical usage, fibrillation most commonly refers to a heart rhythm disturbance in which the electrical impulses in the atria or ventricles become disordered, producing rapid, irregular beats. Atrial fibrillation and ventricular fibrillation can impair the heart’s ability to pump blood effectively. The condition contrasts with flutter, which is a rapid but more organized rhythm. Fibrillate, the verb form, can describe the onset of such activity (the atria or ventricles fibrillate) or, in clinical contexts, attempts to terminate or prevent fibrillation.

In neuromuscular contexts, fibrillation can describe spontaneous, fine, unsynchronized twitches of muscle fibers, such as fibrillation potentials seen on electromyography, or gross tremor following nerve injury. In pathology, denervation or other muscle disorders can lead to fibrillated muscle fibers.

In materials science, fibrillation describes the formation of fine fibers by splitting or tearing of a structure, or the production of fiber-like projections, as in cellulose fibrillation.

Etymology traces fibrillate to fibril, a small fiber, with the suffix -ate indicating a action or process.