Blood clots increase the pressure against which the heart must contract.

I looked through the door and my heart contracted.

The mother's heart contracted in a spasm of pain as she looked at her.

Juliet heard the concern in his voice, and her heart contracted.

Her heart contracted, slowing a beat and then racing out of control.

All at once, a memory surfaced and her heart contracted.

When I spotted the remains of the shelter, my heart contracted.

The human heart is constantly contracting to move blood throughout the body.

First, it was as if his heart contracted with a feeling not unlike fear.

They were on their own, and her heart contracted with fear.