I have not seen any support for PPG or EKG in published Bluetooth specifications.
Both ANT and Bluetooth are general wireless protocols that have further specifications that define how devices can share specific information with interoperability between devices. In the case of ANT, these further specifications are covered by ANT+. In the case of Bluetooth they are specifications such as the "Heart Rate Service". Think of ANT and Bluetooth as defining the sounds used in a vocal language, and ANT+ and specifications such as the "Hear Rate Service" as defining the words and sentence structure.
In ANT+ profiles we allow manufacturers to transmit additional information through manufacturer specific pages. This allows manufacturers to implement additional features for their own purposes. Sometimes manufacturers will start a feature in this way, but then submit to add the feature to the ANT+ profile specification once they are looking for broader adoption. Manufacturers can also choose to create their own ANT profiles outside of the ANT+ space.
Bluetooth similarly allows the development of solutions that are privately maintained.
In terms of vocal language these are equivalent to the creation of a make believe language within a group of children, or the creation of a new slang term that gains broader adoption after appearing in a popular movie.
It is possible that companies out there are communicating PPG and EKG via Bluetooth or ANT, but they are not using a specification shared with all ecosystem members.