The first fully self contained artificial heart has been successfully implanted into a man with end stage heart failure.
The artificial heart is a technological breakthrough and gives hope to patients awaiting a human heart, as supply is limited. The recipient, an unidentified man in his 50s had end stage ischaemic cardiomyopathy, diabetes, and renal failure and was deemed ineligible for a human heart transplant.
The implantation was performed at the Jewish Hospital of the University of Louisville, Kentucky, by a team of 14, led by Drs Laman Gray and Robert Dowling. The team removed most of the recipient's heart and attached the synthetic heart to the remnants of the atria and to the aorta and pulmonary arteries.
Unlike a human heart, the artificial heart first delivers blood systemically and then pumps blood to the lungs for oxygenation. The mechanical heart, known as the Abiocor, is composed of titanium and plastic, is about the size of a softball, weighs 900 g, and is the first to be free of external wires and tubes.
In addition to improving portability and quality of life, the absence of external wires reduces the chance of infection. It is powered by an internal battery, which is charged transdermally through radio frequencies by an external portable battery pack worn by the patient. The battery charges last up to four hours and the device is designed with patient mobility in mind.
The external pack can be removed for up to half an hour, should the patient need to take a shower or change clothes. It also has an indicator panel, which allows the patient to check the battery charge of the heart.
The heart was developed by the Abiomed company of Danvers, Massachusetts. It underwent extensive preclinical testing in animals and was implanted in 40 calves before receiving approval by the Food and Drug Administration for implantation in an initial five patients.
The patients must be aged over 18, have refractory biventricular heart failure, be ineligible for a conventional heart transplant procedure, and have an 80% chance of dying within 30 days without the transplant.
The Abiocor is the second entirely mechanical heart to be tested in humans and represents a major advance over the first artificial heart. The Jarvik-7, introduced in 1982, was unwieldy and air driven and required tubes leading from the patient to huge external compressors.
However, Dr Robert Jarvik, inventor of the first artificial heart, points out that the Abiocor heart, because of its size, cannot be used on small men, children, and most women.
Figure.
AP PHOTO/JEWISH HOSPITAL, JOHN LAIR
Surgeons prepare the new artificial heart for implant