complex array of symptoms syncope chest pain o2 drops

[cheekin]

I'm a 30 yr old male, For the past 2-3 yrs I've been having brief "episodes" where I get suddenly confused, dizzy, and sudden racing pulse that goes up to maybe 110-140..the symptoms usually resolve in less than 10 secs and pulse drops back to normal in 30-45 sec. Finally a discovery, it happened when I was wearing a pulse oximeter and it showed my o2 drop to 83 a split second before the symptoms and racing pulse started...but the o2 went back to 97+ in maybe 15 seconds just like the symptoms went away in 15 seconds,  so now I know my o2 has been probably dropping during every one of those episodes that seem to happen 1-15 x per month. But I have also had racing pulses in my sleep from 1-4 x per month which get even faster, I awake in severe distress but the pulse slows back down in minutes once I wake up and catch my breath and get my bearings.

I have also, in the last 4 months experiencd near continuous heavy squeezing chest pain in the center of the chest about 80% of the time (not severely worse w/ exercise), with lots of palpitations, vague SOB,flopping in my chest as well as general lightheadedness, some dizziness, and what seems to be a heightened sensitivity to adrenaline at times..that is, at times my pulse seems overly responsive to position changes, first standing, etc..
1 particular thing is, frequently, when first standing, my chest and especially head throb very very hard.
I cannot hold a deep breath at all, not even 3 seconds without starting to headrush/blackout.
I have been offered an EP study I'm doubtful if that would work,I have also wondered if I could benefit from a tilt table test, or if I need a coronary cath to figure out this chest pain?

Below is a link to the event EKG that picked up the 160 bpm rhythm in my sleep,take a look:

http://img99.imageshack.us/img99/8752/ekgit6.jpg

Normal 12 lead, echo, and ctx...ANything you can add to this picture for me would be helpful, I am as confused at what to do or what tests to get??

[maggiemag]

Sounds like you have great exercise tolerance!  I would question the accuracy of your oximeter.  Did this significant drop only happen the one time?  If you have heart rate changes, the oximeter can show some funky numbers that are not accurate for a few seconds.  I have to laugh sometimes at what my oximeter shows.  I would reconsider the EP study if I were you.  The EP docs have all sorts of fun ways of inducing arrhythmias!  A tilt table test might be interesting as well.

[cheekin]

Doc, thanks for the reply.
Does the fact that I can sucessfully exercside on a treadmill for 30 minutes with a pulse in the 160's exclude any particular diseases?

[Cleveland Clinic]

The EKG seems to be an SVT of some sort, but it is difficult to tell which kind. It may be IST or AVNRT or AVRT but one can often not tell them apart on a surface EKG. To diagnose and treat this disorder, you need an EP study, during the course of which one can ablate and usually treat the disorder.
However, this is very unlikely the cause of your shortness of breath and desaturation. There are cardiac and pulmonary causes, and whereas an echocardiogram diagnosis the majority of these conditions it may miss some. If there is any right sided dysfunction or enlargment, then you may require a right heart cath to exclude a shunt, or a repeat echo with bubbles for the same reason. A CT, if dedicated to the heart can diagnose the majority of other causes of congenital heart disease which may cause shunting.
But the lungs are probably the number one cause of hypoxia, and besides a chest x-ray you may need PFTs and spirometry, and even a V/Q scan to excluded intra pulmonary shunts or PE.