Yeah, I'm having the same problems as ultrasonicsite. The saliva builds and I can't help but swallow. I remember once I was 'drowning' and started coughing and it ruined my concentration.

And also, I was attempting a WILD last night and as I felt like SP was coming, my heart began to pound so hard and gradually faster but my breathing was normal and relaxed. I'm not sure whether it was just the sound of the pounding being amplified or if I wasn't breathing sufficiently.