But two weeks ago Sam Phayer's world changed forever.

The 20-year-old Warrnam-bool man is recovering from major heart surgery after being diagnosed with life-threatening cardiomyopathy.

He was fitted with a ventricular assist device (VAD) to help pump blood through the left side of his thickened heart. Although the machine will ease the condition, his only cure is a heart transplant.

Yesterday Mr Phayer's fiancee Samantha Wiltshire celebrated her 21st birthday by his bedside at The Alfred hospital in Melbourne.

She told The Standard she was still looking forward to their wedding next Valentine's Day.

"We were hoping to get married at the Warrnambool Gardens," Ms Wiltshire said.

"But if it has to be in Melbourne, if it has to be here (the hospital), then I couldn't care less. It doesn't matter if I come in a tracksuit - I'll do whatever it takes and it gives him a goal."

Doctors diagnosed Mr Phayer's condition by chance two weeks ago. He was initially admitted to a Warrnambool hospital suffering an irregular heartbeat and shortness of breath.

He was initially treated for a chest infection, which healed. But his heartbeat and breathing remained poor.

The diagnosis changed to swine flu but was later found to be cardiomyopathy or an enlargement of the heart.

"It was a shock. He has never been sick and is always on the move, running up stairs," Ms Wiltshire said.

"But luckily they found it. He could have got to 35 and just dropped dead."

Mr Phayer had the VAD installed on Monday in an eight-hour operation at The Alfred.

Everything went to plan, but late that night a blood clot was found in his leg.

He was rushed into theatre where doctors worked for three hours to remove the clot.

Ms Wiltshire said her partner was oblivious to the two surgeries.

"He hasn't known anything for the past two weeks. They plan to wake him up in the next couple of days. It will be a big adjustment for him."