Fibrillations

Part of speech: noun

Definitions

1. A series of rapid, irregular muscle contractions in the heart that can disrupt normal blood flow
2. A condition characterized by twitching or spasms of muscle fibers affecting heart rhythm
3. An abnormal heart rhythm signified by uncoordinated contractions of muscle cells, especially in the myocardium

Etymology: "Fibrillations" is the plural of "fibrillation", a noun built from "fibrilla", a diminutive of Latin "fibra", meaning fiber or filament, with the suffix "-ation" attached. The suffix passed into English through Old French from Latin "-ātiō", which turns a verb's action into a noun. A fibrillation is therefore literally the state or process of becoming made of tiny fibers, and the medical sense grew out of that picture: the heart muscle's fibers twitch independently rather than contracting together. The base "fibrilla" is the key to the word's meaning. Latin speakers used diminutives like this to name something small, so a "fibrilla" is a little thread, and in modern biology it names the threadlike filaments that make up tissues. Physicians applied the same image to the heart, where the muscle fibers quiver out of step instead of squeezing in unison, which is why the rhythm is described as uncoordinated.