Hi Karen and welcome to the forum.

First, let me just remind you here that while I'm willing to provide medical information for purposes of education, it's not prudent for me to give advice from a medical standpoint because it sort of traverses into the area of medical practice. That concept is reckless at the very least when performed over the internet. I'll be glad to provide you with information, but you should not consider "adhering" to it unless it's provided by your primary care physican or specialist. In other words, I'll gladly tell you what I think but not what you should do. Fair enough?

Okay, to your concerns, it would be important to know how often these episodes occur but it sounds more like PAT (paroxysmal atrial tachycardia) rather than anything to do with SVT due to a re-entrant node. With the latter, people tend to have a history of brief episodes beginning early in life that grow more frequent with longer durations and unless your history is positive for such events, I'm going to suggest that it's not the case where you're concerned.

With respect to paroxysmal atrial tachycardia, anyone can experience of run of PAT and it has no basis in the presence of an gross abnormality of any kind. The episodes can last from a few seconds to sometimes 20 or 30 minutes before normal sinus rhythm recurrs and is essentially harmless. The heart rate range you mention would also be common for PAT. Regardless, ablation is not a procedure warranted in such cases, even SVT for that matter unless a re-entrant node has been identified.

The other common presentation is one wherein the patient experiences a single episode at some point and subsequently becomes vigilent to all aspects of performance by the heart. Anxiety disorder with a focus upon one's health is quite common and great efforts are made to try and identify what is thought certain to be an underlying physical cause. This typically causes a yo-yo effect where the patient's emotions are concerned because the reassurance temporarily gained immeidately subsequent to a clean bill of health by the attending physician is not long overcome by anxiety due to the fact that the symptoms have not abated. It is the unwitting and erroneous inclination by the patient to make a direct relationship between the physical symptom being experienced with physical disease of some type, usually heart disease.

If anxiety becomes intense enough and chronic, it can cause dysregulation of the nervous system, which is divided into the sympathetic and parasympathetic tracts. The sympathetic nervous system represents the gas pedal, so to speak, elevating certain bodily processes in response to what the brain senses as a threat based upon feedback it is receiving. The parasympathetic nervous system then, represents the brakes and is responsible for slowing things back down to normal. In the patient with anxiety disorder, there is a fear with unknown attributes or predictability that causes a patient to suddenly sense fear of an immense nature, sufficient enough to engage the "fight or flight" response. In the case of a real threat, the sensations of upregulation by the sympathetic nervous system would be considered normal. In fact, many people have exclaimed after being frightened that "my heart skipped a beat! or my heart was racing out of my chest!" or "I nearly fainted!." Those are are normal consequences of engagement by the fight or flight response, an entirely normal physiological response.

But in the case of a patient with anxiety disorder, the fight or flight response causes the very same physiological symptoms, a thump or skip of the heart, tachycardia and near-sycope or syncopal episodes(fainting), yet there is no recognizable source of the fear in most cases and the patient wrongly assumes that what they are sensing is a constellation of physical symptoms that suggest an underlying physical disease or illness is to blame. It is natural to make the link between physical symptoms and physical disease partly because it's innate and secondly because humans have been socially trained to make such a connection from a very early point in life. Making sense?

Okay, so now for the practical side. Caffeine consumption in the presence of an anxiety disorder only causes further upregulation of the nervous system, so don't expect it ever to be a positive undertaking. It will always make matters worse. As for the exercise and heat exposure, well I don't have to tell you not to do that. You have to be more mindful of limitations, stay well hydrated and limit exercise regardless of variables in how good you feel on any given day. Lack of quality sleep can most definitely impose stress upon the body and many people complain of mild tachycardia as one of the symptoms even in the absence of other features.

Another question is whether you feel anxious about issues other than your cardiovascular health, indicating a need to look further into your anxiety symptoms. My opinion at this point is that based upon the outcome of your tests, your condition is entirely benign and falls into the category of anxiety disorder with somatic features.

You'll be just fine. We'll talk more.

Best regards and Good Health  

It would be my opinion that your condition is caused by dysregulation of the autonomic nervous system in much the same way as other persons here who present themselves with benign palpitations. Since you had no symptoms at all prior to 40 years of age, this would further tend to exclude considerations of the presence of any type of physical abnormality such as a re-entrant node or valve prolapse, or conditions such as Wolf-Parkinson White syndrome known to cause such symptoms.

Your tests are all negative and the thing to remember about these diagnostic tests is that they were developed using algorithms of actual disease, so if the test is negative then it's truly negative and there is no presence of an underlying heart condition that would otherwise explain your symptoms.

Again, I will recap my discussion regarding the intake of caffeine,  over-indulgence in exercise or environmental exposure to heat; Any person can suffer the symptoms you describe as a consequence of these conditions and you should expect absolutely nothing less if you continue. I don't have to tell you that caffeine is a stimulant and everything possible should be done to limit or eliminate it from your diet, using de-caffeinated products instead. Additionally, within your age group, exercise at a moderate pace above 30 minutes per day is absolutely pointless. The above timeframe is all that is necessary to raise metabolism, burn calories and maintain cardiovascular profficiency. The old adage that if a little is good for you then a lot must be even better is no more applicable than it is for any other situation. Moderation is the target. No exceptions.

The reason I'm reiterating all of this is that I'm an old hand with more than 40 years in practice now behind me. People like their habits and their steadfast position in many cases is to try and force the situation to be normal in their specific case while permitting them their transgressions. Countless times I would have constant re-visits or phone-in concerns to my staff because symptoms were persisting with no change. When questioned, they were still doing the very things that were identified as co-factors in their symptoms and yet they rebuffed it, even rejected it, in order to try and have their cake and eat it too.

While it's human nature to resist changing old habits, you should never expect that the factors above will offer no contribution to your symptoms. They indeed will affect matters, sometimes to a high degree. That's a fact.

Lastly, you need to realize that your fears about your heart and any potential for disease as a cause for your symptoms is entirely unwarranted. The battery of tests that you've undergone would absolutely have revealed the presence of even the slightest degree of pathology which would explain the symptom. Furthermore, you need to understand that physical symptoms are not a direct link to physical disease. The human body is extremely complex and does not operate on the level of simplicity that many laypersons rationalize to be the case. It is entirely possible for you to experience physical symptoms as a consequence of a condition such as anxiety disorder and yet have no underlying physical cause. This is why all diagnostic tests for such persons always turn out negative. It is not associated with a physical cause, but resistance to this fact is extremely high. Moreover, the patient's unswerving belief is so strong in this regard that when all tests return negative and contrary to their own instincts, they quickly presume the tests to have missed something. This condition occurs with resounding frequency in the average population and you must come to understand what is actually happening during the episodes you are experiencing versus what your fears are erroneously driving you to believe.

You're going to be just fine and this should represent the juncture for you to begin looking at matters from a different direction. My opinion concerning individuals suffering from such symptoms in similar cases would be seeking out someone to help identify faulty beliefs and thinking patterns which have been driving anxiety to the levels experienced.

And always remember that any concerns regarding symptoms should likewise be discussed with your primary care physician or specialist. The internet is absolutely no source for medical care or advice.

Best regards and Good Health  

     

thank you for such kind words.

I think it's important to realize that the practice of medicine is a constant journey seeking practical wisdom. I say this not because I've arrived, so to speak, but because the discipline and training which keeps patients within the safest corridors can sometimes be too inclusive. It is only through experience and increasing practical knowledge that a physician begins to rely upon the most reasonable and likely possibilities.

As physicians, we see a great deal of illness and disease and the potential to lean toward the more pathological side of diagnoses is unfortunately more the rule than the exception. It stands to reason that if a person presents themselves for evaluation within an environment where illness and disease is so prevalent, then a rather biased viewpoint places odds against, rather than in favor, of more benign causes. This is a characteristic that typically, but not always, changes over time due to experience. Does that make sense?

In any event, you likely have a host of fine and competent physicians at your disposal and based upon the circumstances described, I would suggest that it's as much a systemic issue as it is one of personal characteristics. We certainly don't want anything serious to be overlooked, but by the same token there's a need to sharpen one's skills to the extent that the more practical and reasonable explanations rise to the occasion and constitute the more likely underlying cause for symptoms being presented.

You'll be just fine.  

Best regards and Good Health