Her heart was racing before she pulled the door open.

His heart raced as he considered what the President was doing.

Her heart was racing, though certainly not for fear of him.

His heart still raced each time he thought about it.

Suddenly he felt as if that were the only reason his heart was racing.

I saw the page boy coming, and my heart raced.

Her heart was racing, but everything else seemed to slow down.

His heart raced as he prepared himself for whatever might come next.

Even though his heart was racing, he felt quite calm.

By the end of the session my heart was racing.