معنی کلمه Heart

the organ in your chest that sends the blood around your body:
He's got a weak/bad heart (= his heart is not healthy).
Isabel's heart was beating fast with fright.

More examples

The teacher drew a diagram showing how the blood flows through the heart.
Small amounts of alcohol are held to be good for the heart.
The bullet missed his heart by a couple of centimetres.
I could feel my heart pounding as I went on stage to collect the prize.

They are just waiting for his heart to stabilise.