Heart patient, Jason Dale, can walk the halls of Barnes-Jewish Hospital. It was a different story when the 31-year old Cottage Hills, Illinois man was admitted last month.

"He came to our hospital really very sick. His kidneys had already deteriorated, he had a very hard time breathing," says Dr. Nader Moazami, Washington University cardiac surgeon at Barnes-Jewish Hospital

After beating leukemia as a child, Jason now faced another challenge - he needed a heart transplant. "I started kind of feeling bad about it. A little depressed," says Dale.

Medicines helped his heart pump a little better. He improved slightly but we didn''t think he would have an opportunity to stay alive for longer time until an appropriate heart would become available.

So, Dr. Moazami implanted this device -- the heartmate-II -- as part of a clinical trial. It''s a left ventricular assist device that helps the weak heart pump blood.

"I feel a hundred percent better since I got this. I''m not out of breath any more. I can pretty well walk where I want to walk. I love it," says Dale.

He has a tube coming out to this box that monitors and controls the device. He can plug into an outlet or use batteries when he''s on the go. "Probably the greatest thing with the heart mate two is the size of the device," says Dr. Moazami.

The heart mate-I was noisy and bulky and would have been difficult to fit into Jason. Here''s how the new version works. "The device sits right there, over here it gets connected to the ventricle," says Dr. Moazami. "And then this graft comes around and we sew it on to the major blood vessel in the body which is the aorta. And that carries the blood into the body."

"This is keeping me healthy and functioning until a new heart that will match me will come in," says Dale, who was the first patient in Missouri to get implanted with the new heartmate-II. It will allow him to live at home until a new heart becomes available. He''s going home from the hospital today.