fibrillation

noun

fi·​bril·​la·​tion ˌfi-brə-ˈlā-shən  ˌfī- 

1

: an act or process of forming fibers or fibrils

2

a

: a muscular twitching involving individual muscle fibers acting without coordination

b

: very rapid irregular contractions of the muscle fibers of the heart resulting in a lack of synchronism between heartbeat and pulse

Examples of fibrillation in a Sentence

Recent Examples on the Web

About 1,300 people experienced atrial fibrillation (also called afib), an irregular and usually very rapid heart rhythm. —Tom Gavin, EverydayHealth.com, 30 Jan. 2025

While the exact cause of the condition is unclear, atrial fibrillation most often occurs in older individuals or those with existing chronic conditions. —Rachel Raposas, People.com, 13 Jan. 2025

About 2 million people undergo open heart surgery yearly for different heart conditions, including coronary artery disease, atrial fibrillation, or heart failure.1 What's the Purpose? Open heart surgery allows your surgeon to make a large incision (cut) in your chest to access your heart. —Suchandrima Bhowmik, Health, 17 Oct. 2024

Inflammatory stress impacts heart rate variability and increases the risk of atrial fibrillation. —Tom Gavin, EverydayHealth.com, 30 Jan. 2025

Word History

First Known Use

1845, in the meaning defined at sense 1

Medical Definition

fibrillation

noun

fi·​bril·​la·​tion ˌfib-rə-ˈlā-shən  ˌfīb- 

1

: an act or process of forming fibers or fibrils

2

a

: a muscular twitching involving individual muscle fibers acting without coordination

b

: very rapid irregular contractions of the muscle fibers of the heart resulting in a lack of synchronism between heartbeat and pulse see atrial fibrillation, ventricular fibrillation