Status of ekg for series 4 watch?

To be added later this year.

Apple has already replied, at the launch event they said it would be available later this year.

Whitefeather1530 wrote:

Hoping Apple would reply, not the public speculating. This one of the main reasons I bought it.

This is a user-to-user technical support forum. Apple doesn't reply here to this sort of question.

Until Apple makes a public announcement, no one would know.