unanswered feelings

In 1991 what started as a normal check-up with the family doctor I found out I had a past heart attack. Which led to a double by-pass the same year, no problems after the surgery. In 1996 I was in a propane gas explosion at work that killed my superviser. I  had no physical injury, I went for consoling and was diagnosised as having P.T.S.S.. Since the explosion which happened in the winter I get heart palpitations every winter out of the clear blue. The doctor said it is anxiety and prescribed Xanax to take as needed which helps. In 2004 at work I was trapped in an extremely dusty atmosphere with only a small dust mask. The mask became clogged and I could not breath. Just before the dust cleared I felt a quick and sharp pain in my chest for a second or two. I removed the mask and started taking large breaths of air. A minute or two later I felt something I never felt before in my life. It's hard to explain, almost like fainting for 1/2 of a second I never fainted before so I'm not sure. Like flipping a light switch off then on that quick. It was late afternoon and this feeling happened twice with in minutes of each other. I felt normal no palpitations, no dizziness, no pain or discomfort just normal so I did'nt do or say anything. Then the next day at work in mid day sitting in a chair relaxing it happened again and again just twice and close together. I thought in 2 days my family doctor will have office hours I should make an appointment. But on the 2nd day after the incident the feeling started again but this alot more than 2 times. After about 10 to 15 times of this feeling I could now feel my heart beating differently so I called 911. I did'nt have any pain just scared now I know somethings wrong. When the paramedics came I was sitting down they asked if I could get on the stretcher myself, I said yes and had no problem. In the ambulance on thr way to the hospital after being hooked to some equipment it was determined to hit me with the pads. At the hospital I was diagnosised with V.T., and soon after got an I.C.D.. My question is: I understand the diagnosis from the hospital but nobody has been able to explain what was happening in the beginning. The sharp pain I felt the 1/2 second feeling like a light switch going off then on and then the 2nd day 10 to 15 times untile I felt something wrong with the heart.  Any help would be greatly appreciated! THANK YOU

[Wisconsin2007]

This would only be a guess, but my guess is you were in Vtach during those "blacking out" moments, and your brain was not receiving enough oxygen, and you were, in fact, passing out.  But maybe your heart returned to a normal rhythm just before you lost consciousness.  And whether it's lucky or unlucky, I'm not sure, but it would seem that you're one of the people who doesn't feel all the funkiness their hearts can cause.  I feel everything, which I guess is good, as it gives me a leg up on staying alive, I suppose.

The short, sharp pain would be hard to determine.  Could've been gastrointestinal, could've been something with your heart, though those pains don't usually come and go that quickly.