What does cardioversion mean?
Cardioversion is a medical procedure used to restore the heart's natural rhythm when it has fallen into an abnormal pattern, most commonly atrial fibrillation or other supraventricular tachycardias. It can be performed in two ways: electrical cardioversion delivers a carefully timed, synchronized electric shock to the chest through paddles or adhesive pads, while pharmacological cardioversion uses antiarrhythmic medications to coax the heart back into its regular beat. The term derives from combining "cardio-" (heart) with "conversion" (turning back), reflecting the goal of converting an abnormal rhythm into a sinus, or normal, one. Cardioversion is distinct from defibrillation, which uses unsynchronized, higher-energy shocks for cardiac arrests; cardioversion instead targets patients whose hearts are still beating but beating incorrectly. The word belongs firmly to clinical register — you will encounter it on hospital consent forms, cardiology reports, and emergency protocol documents rather than in casual conversation.
nounThe restoration of a normal heart rhythm from an abnormal rhythm, either by delivering an electrical shock to the chest or by administering antiarrhythmic medication.
- The restoration of normal heart rhythm by synchronized electrical shock.
- The restoration of normal heart rhythm by antiarrhythmic drugs (pharmacological cardioversion).
"The patient's atrial fibrillation was successfully treated with cardioversion."
"After two failed attempts at chemical cardioversion, the cardiologists scheduled an electrical procedure."
"Emergency department protocols call for immediate synchronized cardioversion in unstable patients with tachyarrhythmias."
Rarely pluralized; typically treated as an uncountable procedure name. Plural forms appear mainly in clinical research discussing repeated procedures.
"The study followed patients who required multiple cardioversions over five years."
In synchronized cardioversion, the machine waits for the exact right moment in the heartbeat to fire — deliver the shock at the wrong instant and you could make things worse.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cardioversion
Cardioversion is formed from the combining form "cardio-", from the Greek "kardia" meaning heart, joined to "conversion", ultimately from the Latin "convertere" (to turn around). The term emerged in twentieth-century medical usage as electrophysiology advanced and clinicians developed techniques for deliberately restoring normal cardiac rhythm. Its cognates include other Greek-derived cardiac terms such as "cardiac" and "cardiogram", alongside Latin-rooted words like "conversion" itself.
How cardioversion is actually used
A technical medical term used almost exclusively in clinical and healthcare contexts; it is not part of everyday informal speech. It appears frequently in cardiology literature, patient-education materials, and hospital documentation.
Easily confused with cardioversion
Defibrillation treats life-threatening arrhythmias like ventricular fibrillation with unsynchronized shocks, while cardioversion is a timed, synchronized shock or drug therapy used for less immediately critical rhythm disturbances such as atrial fibrillation.