fibrillation
noun
fi·bril·la·tion
ˌfi-brə-ˈlā-shən 
ˌfī-
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
Those exposed to the brightest light also had a 47% greater risk of having a heart attack and a 32% higher risk of developing atrial fibrillation.
—
Kristen Rogers, CNN Money, 27 Oct. 2025
Six days later, on February 18, Gene’s death is believed to have occurred when his pacemaker recorded an episode of atrial fibrillation.
—Joy Williams, Harpers Magazine, 24 Oct. 2025
According to the American Heart Association, CKM syndrome can lead to atrial fibrillation, coronary heart disease, disability, kidney failure, peripheral artery disease, stroke, heart failure and even early death.
—Rachael O'Connor, MSNBC Newsweek, 21 Oct. 2025
When he was diagnosed with atrial fibrillation, Cuban used AI to track his medications and his workouts.
—Marco Quiroz-Gutierrez, Fortune, 2 Oct. 2025
See All Example Sentences for fibrillation
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Kristen Rogers, CNN Money, 27 Oct. 2025
Six days later, on February 18, Gene’s death is believed to have occurred when his pacemaker recorded an episode of atrial fibrillation.
—Joy Williams, Harpers Magazine, 24 Oct. 2025
According to the American Heart Association, CKM syndrome can lead to atrial fibrillation, coronary heart disease, disability, kidney failure, peripheral artery disease, stroke, heart failure and even early death.
—Rachael O'Connor, MSNBC Newsweek, 21 Oct. 2025
When he was diagnosed with atrial fibrillation, Cuban used AI to track his medications and his workouts.
—Marco Quiroz-Gutierrez, Fortune, 2 Oct. 2025
See All Example Sentences for fibrillation
Cite this Entry
“Fibrillation.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fibrillation. Accessed 28 Oct. 2025.
Copy CitationMedical Definition
fibrillation
noun
fi·bril·la·tion
ˌfib-rə-ˈlā-shən
ˌfīb-
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
Love words? Need even more definitions?
Merriam-Webster unabridged
Share