Until the first few dives were over and we were all comparing how much air was still in our tanks when we came up.. normally my wife and I have about the same amount of air remaining.. this trip she would have 900-1000 pounds of air in her tank and I was in the 400 - 500 psi range, meaning I had sucked quite a bit more air than she had.. Reason being - my guess anyways - was that a valve blockage that was discovered after a dive trip in 2014 (where I was having the same issue sucking air and never able to catch my breath) had gotten worse..
I did have an EKG Tuesday, which was abnormal, but haven't been able to schedule an appt with a cardiologist yet to get another scan of the blockage..
So, to answer your question, I didn't really know before the trip, although I had a sneaking suspicion because I always run and lift weights before a dive trip and this time after running I was sucking air pretty bad and it never got better after 6 weeks of running..
Friendship is like peeing your pants.. Everybody can see it, but only you can feel the warmth..