How common are heart attacks in layer chickens?

[1stTimeChicken]

We found one of our almost 5 year old Australorp hens dead in the coop this morning. Definitely not predator related. Not sure when she may have died, but she was rigorred already. She was laying on her back, the neck feathers were ruffled a bit, the wings looks a little spread, not tight against her body.
From everything I read through googling, sounds like it was a heart-attack/flip-over disease, but further research showed it more of a thing with broiler chickens, not older laying hens.

So how common are heart attacks in regular chicken breeds?

 

[Nani87]

Regardless of the cause I am sorry for your loss.

 

[nuthatched]

Soery about your hen. Not very, but it depends on the diet.
the position if the body has no indication of reason of death.

 

[Eggcessive]

If you could do a home necropsy to look at the organs, or keep the body cold to go into the state vet lab Monday, you could find out what might have killed her. At 5 years, a reproductive issue such as salpingitis or cancer might be possible. Was she still laying? How was her crop feeling? Was her lower belly enlarged with yellow ascites fluid? Doing a necropsy on hens I have lost has been very educational. There are videos online, and you can do a brief one posting pictures of the abdominal organs here for opinions. Sorry for your loss.