What does defibrillated mean?
"Defibrillated" is the past tense of "defibrillate", a medical verb meaning to deliver a controlled electric shock to the heart in order to halt ventricular fibrillation — a chaotic, ineffective quivering of the heart muscle — so that a normal rhythm can resume. The word comes from "fibrillation", itself derived from Latin "fibra", meaning fiber, since the condition involves individual muscle fibers contracting out of sync. It appears almost entirely in clinical contexts: paramedics report that a patient "was defibrillated twice", and medical records note how many times a person was defibrillated during resuscitation. Though technical in tone, it has entered wider public awareness through medical dramas and first-aid training, especially with the spread of automated external defibrillators in public spaces. Knowing the word helps readers interpret emergency care accurately and understand one of modern medicine's most dramatic interventions.
verbPast tense and past participle of "defibrillate": to administer an electric shock to the heart using a defibrillator in order to restore a normal heartbeat, typically during cardiac arrest caused by ventricular fibrillation.
- To have stopped ventricular fibrillation by delivering an electric shock to the heart with a defibrillator.
"The paramedics defibrillated the patient within minutes of his collapse, and his pulse returned on the way to hospital."
"Doctors defibrillated him three times before his heart regained a steady rhythm."
"She had been defibrillated on the roadside by a bystander using a public automated external defibrillator."
The word literally means to stop your heart's fibers from quivering — because in cardiac arrest, the heart isn't still, it's shaking uselessly like a bag of worms.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of defibrillated
The word traces back to Latin "fibra", meaning fiber or filament, which also gives English "fiber", "fibril", and "fibrillate". "Fibrillation" was adopted into medical English to describe rapid, irregular twitching of muscle fibers, particularly in the heart. The verb "defibrillate" was formed in the early twentieth century alongside the development of electrical countershock therapy, combining the negative prefix "de-" with "fibrillate" to mean stopping that fibrillating activity. Its cognates therefore include "fibril", "fibrillate", and "fibrous".
Related word forms
How defibrillated is actually used
Strictly medical and technical register; used almost exclusively by clinicians, paramedics, and emergency-medicine writers rather than in everyday speech, where phrases like "given an electric shock" are more common.
Easily confused with defibrillated
"Defibrillator" is the noun for the machine that delivers the electric shock, while "defibrillated" is the verb describing that action being performed.