Okay, welcome to the forum. I've read your posting and concerns.

You need to pause and relax. You are indeed in no danger whatsoever and there is nothing wrong with your heart. The palpitation events are being induced by wayward impulses from the vagus nerve, which incidentally also innervates your GI tract and is termed the pneumogastric  nerve at that level.

The reason that the events seldom occur during evaluation or monitoring is quite simple. Vagus nerve-induced palpitation events arise in connection with parasympathetic nervous activity. The central nervous systems is made up of two basic systems, the sympathetic and parasympathetic. The sympathetic nervous system is responsible for increasing heart rate, respiration, increased visual acuity, vasoconstriction, reduced motility and bowel function and other aspects of physiology which basically prepare the body for action. You can think of the parasympathetic nervous system then as sort of the brakes and responsible for decreasing heart rate, respiration, visual acuity, vasodilation and increased motility and bowel function. Depending upon the system, certain functions increase while others decrease and vice versa.

The vagus nerve, cranial nerve X, is the largest mixed nerve in the body and its actions are parasympathetic. Whenever the nervous system is under constant strain from various causes, including stress, anxiety and even illness, the potential for wayward nerve impulses to occur is increased. These inappropriate nerve impulses travel along the vagus nerve until reaching the terminal endings and eliciting a response by the organ being innervated, in this instance the heart. The heart is as much a muscle as it is an organ and the heart muscle tissues simply respond to the nerve impulse much in the same way a random nerve impulse in cranial nerve III or VIII cause the eyelid muscles to twitch.

Just as a twitching eyelid is incapable of damaging the eye or causing loss of function, ie sight, so it is with the heart muscle responding to a wayward nerve impulse that is otherwise incapable of producing any type of dangerous arrhythmia or cardiac event of any type. It's merely a muscle twitch. The events will never produce anything more than the sensation itself.

When under evaluation by a physician, most persons are concerned as to what may be found and as a consequence, their sympathetic nervous system becomes dominant while the parasympathetic nervous system is suppressed and less influential. Once it's been determined that nothing is found to be wrong and you arrive back home to rest, the parasympathetic nervous system becomes dominant and the potential for palpitations to arise is increased.

Disturbances of the GI tract can produce palpitation events based upon the fact mentioned earlier regarding the vagus nerve connection with GI function. Realize that an empty stomach can produce GI difficulty just as much as an overfilled stomach. Basically, any circumstance in which the intestines and stomach create upward pressure against the diaphragm, the likelihood of palpitation events increases. A reduction in GI symptoms will directly correspond with a reduction in palpitation events. Belching, changing body positions, eating if the stomach is empty and similar stimulation can often bring about relief.

You're going to be just fine and there's nothing actually wrong with your heart. The tests will return negative and you should use this opportunity for insight in moving forward with your life. Those who dwell upon such matters and become fixated with irrational beliefs concerning the palpitations can cause great disruption in their daily life and even the lives of those around them in certain instances.

Spend time reading through the forum and you'll see that you are not alone with respect to experiencing vagus nerve-induced palpitation events.

Best regards,

Rutheford Rane, MD (ret.)