Hello Brett,
Yes. I have read those accounts too.
However, “hadaya vatthu” is not the same as the hadaya or heart.
The heart is part of the physical body. Hadaya vatthu is part of the mental body (gandhabba).
– While the mental body is staying with the physical body, hadaya vatthu OVERLAPS the heart.
However, sometimes the mental body separates from the physical body even while the person is living, as in the cases of Near-Death Experiences (NDE).
– In such cases, hadaya vatthu comes out of the physical body, as part of the gandhabba.
Still, the mental body and the physical body can affect each other to some extent. The anecdotal evidence of some such effects is what you mentioned.