The mechanical heart assist device, also known as the left ventricular assist device (LVAD), is implanted as a bridge to heart transplantation.

It is usually used as a last resort for heart failure patients and it keeps them alive until a suitable heart comes along.

According to Thoratec, the company that manufactures the Heartmate II, there are patients who have lived for more than eight years with the device.

One of the risks, however, is blood clotting and, when that happens, the device will have to be replaced.

To date, only 65 heart transplants have been performed at the National Heart Centre Singapore (NHCS), the only place in Singapore that does heart and lung transplant surgeries.

There are 23 people on the waiting list for a new heart, including Mr Kevin Wong.

NHCS' senior consultant of cardiothoracic surgery Tan Teing Ee said: "Patients who were incapacitated by the symptoms and recurrent hospitalisations due to advanced heart failure have gone on to lead almost normal lives, and some have even gone back to work.

"To date, NHCS has performed 67 implantations for the newer generation LVADs and Kevin is just one of many who have done well."

The newer generation LVAD, called the Heartmate II, is a golf ball-size device that works like a jet engine.

It is implanted under the heart with a connector drawing blood from the left ventricle (pumping chamber) of the heart and pumping it into the aorta continuously via a conduit.

Although the device is small, it can pump six to 10 litres of blood a minute, more than the average requirement of four to five litres for a healthy adult.

The pump and its connections are implanted during open heart surgery. A computer controller, a battery pack and a reserve battery pack remain outside the body.