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
The certificate listed atrial fibrillation and pulmonary hypertension as contributing conditions.
—
Jami Ganz, Mercury News, 6 Feb. 2026
Carter also suffered from atrial fibrillation, an arrhythmia resulting in rapid heartbeat, and pulmonary hypertension, a progressive disease that can result in high blood pressure.
—Anna Kaufman, USA Today, 6 Feb. 2026
Other research has shown that people who received the shingles vaccine were 23 percent less likely to develop issues like heart attack, stroke, and atrial fibrillation than those who were unvaccinated.
—Emily Kay Votruba, EverydayHealth.com, 22 Jan. 2026
My heart has an irregular rhythm, a condition known as atrial fibrillation that requires me to take the blood thinner Eliquis.
—Chicago Tribune, 18 Jan. 2026
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.
Jami Ganz, Mercury News, 6 Feb. 2026
Carter also suffered from atrial fibrillation, an arrhythmia resulting in rapid heartbeat, and pulmonary hypertension, a progressive disease that can result in high blood pressure.
—Anna Kaufman, USA Today, 6 Feb. 2026
Other research has shown that people who received the shingles vaccine were 23 percent less likely to develop issues like heart attack, stroke, and atrial fibrillation than those who were unvaccinated.
—Emily Kay Votruba, EverydayHealth.com, 22 Jan. 2026
My heart has an irregular rhythm, a condition known as atrial fibrillation that requires me to take the blood thinner Eliquis.
—Chicago Tribune, 18 Jan. 2026
See All Example Sentences for fibrillation
Cite this Entry
“Fibrillation.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fibrillation. Accessed 18 Feb. 2026.
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
