WATCH: Best reaction to pregnancy announcement ever

A soon-to-be grandmother had the best reaction ever to hearing the news that she's going to be a grandmother!

"My wife and I told our mom this past Christmas that we were expecting our first child," Nathan Kunst of Rochester Hills, Michigan posted on YouTube. The couple had filmed many of their family members' reactions, but Kunst's mother's reaction topped them all.

Kunst's mother, Nancy, is seen opening the present on video and then outbursts with an ear-piercing scream. She's visibly excited and her legs are shaking as she screams in disbelief.

"Heart attack, please, what's happening," Nathan is heard off-camera saying as the family laughs.

Watch the announcement below (mobile users click here):