Forget all those piffling little drugs that may or may not be involved in the ‘Tour, we could be on the verge of a whole new performance enhanced age.

The US Food and Drug Administration has approved the experimental replacement of patients’ hearts with mechanical devices and at least five expert cardiac centres across the US are now gearing up for the operations. “It will be unlike anything carried out on a human before,” says Robert Kung, who developed one of the devices for Abiomed.

Abiomed’s artificial heart fits entirely inside the chest, with a battery pack positioned in the recipient’s thorax. “Our aim was that you’d be able to line them up with other people and see no external difference,”

The heart consists of a motor that operates a pump using membranes and valves made of a strong, flexible plastic invented by the company. “It has to flex over millions of cycles and be compatible with blood, to avoid clotting,” says Kung. Additional electronics use pressure measurements to determine when the heartbeat needs to speed up to cope with the demands of exercise or sudden alarm in the patient. The whole ensemble adds about two pounds in weight compared to the original ticker.

The main drawback seems to be the internal lithium battery pack which only lasts about one and a half hours. They can be recharged from a portable external pack that passes energy through the patient’s skin by a current induction method, but presumably this run time drops when the heart beats faster, and could be nasty if your recharger gets caught up in a power cut. Plans to develop a dynamo powered set up for cyclists have not yet been confirmed.