English Reference

Word

fibrillation

Phoneticsfib·ril·la·tion

US/ˌfɪbɹɪˈɫeɪʃən/

UK/fˌɪbɹɪlˈeɪʃən/

Definition

n. a fast, irregular, and uncontrolled beating of the heart. It is a serious medical condition that can be life-threatening if not treated quickly.

n. a rapid, irregular, and uncoordinated contraction of the heart muscle, typically occurring in the atria or ventricles. It is a serious arrhythmia that can lead to cardiac arrest if not corrected.

Examples

“The doctor checked for signs of heart fibrillation.”

“Emergency responders used a defibrillator to restore a normal heart rhythm after the patient suffered from ventricular fibrillation.”

“While atrial fibrillation is more common and often manageable with medication, ventricular fibrillation is a medical emergency that requires immediate electrical intervention to prevent sudden cardiac death.”

Examples

simple

“The doctor checked for signs of heart fibrillation.”

contextual

“Emergency responders used a defibrillator to restore a normal heart rhythm after the patient suffered from ventricular fibrillation.”

complex

“While atrial fibrillation is more common and often manageable with medication, ventricular fibrillation is a medical emergency that requires immediate electrical intervention to prevent sudden cardiac death.”

Real-World Examples

“Direct oral anticoagulants cut the risk of serious clinical events by 69% in atrial fibrillation patients with an intermediate risk of stroke, according to the randomized SINGLE-AF trial.”
ScienceDaily · 27 Sept 2026
“Newer blood thinners may do more than prevent strokes in people with Alzheimer’s disease and atrial fibrillation.”
ScienceDaily · 18 Sept 2026

Etymology

From fibrilla + -ation.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry

Level
C1 · Advanced
Frequency
Occasional
Updated

Scan code

englishreference.com/q/fibrillation

English Reference