My doctors tell me that my irregular heartbeat is not being caused by my heart or its electrical system?

A little over a month ago I had a caffeine induced tachycardia and had been awake for a little over 48hrs. I have been put through tons of testing and they can't figure out why my resting and active heart rates are irregular and faster than they were before. They told me that my sinus node is functioning properly and that something else is making my heart beat fast. I cut myself of all stimulants and changed my diet and a host of other things and have had only minimal improvement. Before this happened I was a perfectly healthy 26 year old man. Now I feel like I am 80 with this heart rate symptom. Could I have triggered an imbalance of my nervous system that is causing this or are my doctors just blowing me off because I am young and my resting heart rate is still in the "normal range" Example: My resting heart rate before this was 55-60, now it is 75-80.
So, do you think I damaged my SA or AV nodes or messed up my nervous system with my stupid caffeine/no sleep bender?

I already went to a cardiologist, had several EKG's, echocardiogram, CT scan, Holter Monitor. The Cardiologist agreed that my heart is beating faster than it was before, but said that something else is causing it.
Possible nervous system dysfunction?
Developed a hypersensitivty to adrenaline? I have all the symptoms of Mitral Valve Prolapse Syndrome, but was told from the echocardiogram that I don't have a prolapsed mitral valve.

I don't see anything particularly wrong with the resting rate, in terms of still having a healty sinoatrial rate (60-100). you'd have to look at EKG derivations to be able to certify any problem with the sinoatrial or atrioventricular nodes but I'm sure your doctor has looked at this already? now It's fairly improbable that caffeine would induce permanent damage to the NCX and cardiopulmonary nuclei in the medulla oblongae. Maybe (but it sounds fairly improbable) the caffeine hasn't completely been eliminated (how recent was this). maybe you've stopped excercising in fear of the condition? excercise keeps basal heart rates low. maybe you also take some average stimulants (like plain old sugar), and don't realise it. But seeing how self conscious you've become, you could just be inducing this mentally on yourself.

Edit:
To potentially agree with coffee quaffer's possibility, it would be nice to know if you've had any other symptoms, like weight loss, profuse sweating, hyperactivity, etc. that could signal a primary hyperthyroidism or something secondary to hipofisiary hyperfunction.

I had no previous time to answer but I suggest you head on to another doctor soon. this could easily be a common aldosteronism or adrenal gland problem that is common in women. if i can do anything else, andreji_menez@yahoo.com Report It

If you are in doubt, please do not hesitate to seek a second opinion. If your current doctor acts offended by this, then change physicians.

There's so many things that can cause that that it'd be impossible to diagnose it without a lot of testing. But the 48 hours of no sleep and caffeine won't damage your heart. You may have brought out a potential future problem, which is good that you found it now.

Your Oxygen level in you blood can have an effect on your heart which will cause tachycardia. I have it and take several medications to control it, and it took a couple of years before they were able to find the right balance of meds. If I don't take them my heart goes completely wacky but it's not really life threatening unless it's long term. Your Cardiologist may put you on a 24 hour heart monitor and decide what to do after that. Maybe nothing, at your age you can get it under control with excercise, but definitely see a Cardiologist first and if one has no answers go to another.

You may want to see an acupuncturist. There is a specific point - PC6 - which is a bi-phase heart point, meaning it will balance the heart beat if it is fast or slow. Acupuncture at PC6 accelerates bradycardia and decelerates tachycardia. Another bonus of acupuncture is you won't have to take an expensive prescription drug cocktail for the rest of your life.

One of your doctors has probably already investigated this, but I wonder about your thyroid function. A simple blood test would tell you more.

As others have mentioned, your resting heart rate is fine. Is it possible that your frightening experience has left you overly sensitive, and that you're overly focused on your body?

Sleep deprivation can definitely cause tachycardia, by the way.

I wonder if it could be anxiety causing this? I would go for a second opinion until you are satisfied with the answers you receive. I also wonder if you could have a kidney problem affecting your electrolytes, but I suppose they have checked the electrolytes on the lab reports. Good luck to you!

Did they check your blood sugar too? Sometimes, low blood sugar (or hypoglycemia) can cause symptoms such as those you were alluding to.