A patient implanted with the world's first self-contained mechanical heart is resting comfortably after a seven-hour operation, says a hospital in Louisville, Kentucky.
The procedure is the first major advance in the development of an artificial replacement heart in nearly two decades.
The device replaces the lower chambers of a patient's failing heart with a plastic-and-metal motorised hydraulic pump which weighs 1 kg and is about the size of a grapefruit.
It is the first artificial heart to be free of wires connecting it to the outside.
Hospital officials would not disclose the name or gender the patient, who is seriously ill.
Unlike existing devices, which serve as a temporary solution to extend a patient's life, the AbioCor heart is designed to be a fully functioning replacement heart.
The AbioCor contains a small electric motor attached to an implanted battery and is designed to last for years. Patients could wear a battery pack or plug into an electrical outlet to recharge the heart's battery.