In atrial fibrillation, the electrical impulse of the heart is not regular. 1  Parts of the heart cannot contract in an organized pattern. 2  As a result, the heart cannot pump enough blood to meet the body's needs.
Synonyms, crossword answers and other related words for IN A NUTSHELL. summed up briefly; gave the facts in a nutshell; just tell me the story in a nutshell; explained the situation in a nutshell.
crazy, 1846, from earlier be nutts upon be very fond of (1785), which is possibly from nuts (plural noun) any source of pleasure (1610s), from nut (q.v.). Sense influenced probably by metaphoric application of nut to head (1846, e.g. to be off one's nut be insane, 1860). Nuts as a derisive retort is attested from 1931. Connection with the slang testicle sense has tended to nudge it toward taboo.