By Caroline Ryan
BBC News Online health staff
Researchers are developing a "heart blanket" which could give patients with heart disease a better quality of life.
Bands would squeeze the heart in the same way as a belt is tightened
The aim is to be able to give underperforming hearts an extra boost as and when they need it.
The artificial heart muscle being developed in Leeds could mean patients no longer need transplants if they have an under-performing heart.
Heart disease is Britain's biggest killer. Each day 700 people suffer a heart attack and 300 die from heart disease.
At the moment, patients can be offered mechanical pumps, but these are usually only used as a temporary measure while patients await transplants.
The pumps use an electric motor to push blood through a pump, but this can cause damaging plaque to build up in blood vessels.
In the past, doctors also used a muscle from the back to help the heart which can be stimulated by a pacemaker, but it wore out more quickly than the cardiac muscle, so it is no longer seen as a solution by heart specialists.
The artificial muscle being developed by the Leeds researchers mimics the way that the heart itself works.
Cardiac muscle uses chemical bonds to pull the filaments together.
The artificial muscle uses minute ultrasonic motors which joined together to form bands around the heart. These bands would then form a "blanket" covering the heart.
The researchers say the device could boost the heart by at last 10%
When they are joined together, a high-frequency voltage is applied which makes them vibrate in a wave pattern, replicating the movement of heart muscle.
The researchers liken the action of the device like the tightening of a belt. It is hoped it will be possible to attach the device to the heart.
It should be possible to use pacemaker technology to control the device, powered by an external battery.
This technology could detect how effectively the heart is working, and when the artificial muscle needs to kick in.
Dr Martin Levesley, a lecturer in dynamics and control at Leeds University, told BBC News Online: "The big advantage of a device like this is that there are a lot of heart pumps that bypass the heart - but they have contact with the blood.
"The whole point of this is to have something that makes use of the heart itself.
"It doesn't come into contact with the blood, so you don't have any damage to the blood cells."
He added: "We are still at a stage where we are looking at the mechanics; how to structure the device, how do we tell it how much to squeeze and tell it when someone is exercising."
Dr Ben Hanson, a research fellow who is also working on the artificial heart muscle project, said the device should be able to boost the heart's power by at least 10%.
He said the device could help patients who had suffered heart attacks, affecting the pumping capacity of their heart.
"This leaves the heart under-performing and is typical of the type of condition that we hope to be able to assist."
The research has been funded by the National Heart Research Fund.