The more active you are, the better your heart works.

It also helps your heart work the way it's supposed to.

These tests will let the doctor know how well your heart is working.

She thought the words came out quite normally, considering how her heart was working so hard.

It turns sound waves into pictures that show how well your heart is working.

He says: "Most people have the idea that the heart is working all the time.

It provides an estimate of how well the heart is working.

The heart can work so hard that it becomes sick.

Put it all together - your heart is working again.

The harder your heart must work, the more oxygen it needs.