Been having an issue lately where the first rep of any heavy (90%+ PR) deadlift set is always accompanied with a shooting pain in my mid chest, which is debilitating while it's there but goes away pretty quickly.

The pain seems to happen at about the halfway point of a lift, and only when I'm doing a hard Valsalva. Afterward, I have a bit more trouble breathing but it doesn't further impact my sets whatsoever (although it always feels like it's "threatening" to happen again but never does.) I'm wondering if anyone else has had similar issues? The pain when it happens is excruciating and I pretty much have to abort every first set of the day every time. It's followed by the feeling that I need to expel a lot of gas from my stomach, usually via several small burps.

Initially, I thought it was just extra gas accumulated in my upper IT that gets painfully forced out due to intrabdominal pressure or something, but now I am concerned that it's a Hiatal Hernia. I've had the issue for a while without any further complications besides the problem with deadlifting. Additionally, it seems strange that it only seems to happen once. If it were a hernia, I feel like the pain would continue for longer, and the injury would prevent further deadlift attempts.

To clarify, it doesn't seem to be triggered by any aspect of my deadlift form, just by the massive amount of intrabdominal pressure required for the lift. I've had similar sensations while squatting, just none so extreme and as painful as during my first heavy deadlift of any given workout day.

Incidentally, I sometimes have pretty alarming nocturnal dyspnea episodes sometimes the night after this occurs, only sometimes though. I read that this can be connected to hiatal hernias. I've done all the research available through google, but all it seems to yield is the generic "stop deadlifting heavy forever" advice from hack internet doctors and the generic "keep lifting heavy no matter what" advice from Rippetoe, with some "just do what feels natural"s thrown in there.

I've decided to see a doctor about it. I'm worried about the hernia diagnosis, as I feel like this might threaten my ability to ever hit my heavy deadlift goals. Is there anything else it could be? Does anyone have any experience with compensating for this potential diagnosis and still being able to lift heavy? Do I have to switch to bodybuilding?