I am a 60 yo man with history of bypass surgery 5 years ago due to blocked LAD at bifurcation. Since then have been essentially asymptomatic even during frequent heavy exercise such as running and cycling. Resting pulse is in low 40's which is where it has been for years. During the last 6 months, I have had perhaps four occasions of dreaming that I cannot get a breath, like I had a severe cold. It did not wake me up. When I did awake, I was in no way congested. Could it be my heart was stopping or taking long pauses that resulted in this? I don't think a holter would be effective in catching it as it may be months between episodes. My heart rate does respond to heavy exercise sometimes getting as high as 175. My mother had a somewhat similar exeperience last year and got a pacemaker the next day. Her problem was AV block though. I am on 25mg Toprol for occasional Afib which seems to be in remission right now. I had a routine EKG a few weeks ago which was apparently OK. Thanks in advance for your comments.