sporadic/nocturnal rapid heartbeats

[numa555]

My 17 year old son has occasional episodes of racing heartbeats. He has been aware that they happen during the day with no warning or exercise related. He is in very good physical shape.
Ultrasound is fine, ekg fine -  Holter monitor displayed 10-12 episodes per night where his heart rate went from 40 to 80-90. The episodes last 10-15 seconds at the increased rate and then return to normal.

Any thoughts?
Is it possible that cell phone, computer, etc. could be the cause? There is also a family history of heart disease from both parents.

[numa555]

Thank you! Your response is very helpful. We will be following up with a cardiologist but wanted to make certain we weren't missing anything.

[Jeffrey R Boris, M.D.]

Dear Numa,

In the absence of being able to further evaluate your son or review the data that I would need myself, I can give you only a limited set of thoughts on this.  For starters, I do not believe that this has anything to do with the electronic devices in his life.  The most common reason that I see for adolescent patients who have this is relative dehydration, in which they don’t drink enough fluid.  If the tank is not as full as it should be, the autonomic nervous system, which is the part of the nervous system that controls heart rate and blood pressure (among other things), tries to increase blood pressure and/or heart rate if it senses that things are lower than normal.  Another potential reason for this is caffeine intake, which is a myocardial irritant and can both speed up the heart as well as lead to early abnormal heart beats.  That said, it sounds as if the Holter monitor did not have any early abnormal beats.  However, you also mentioned that his symptoms occur during the day whereas the Holter findings were noted at night.  Another reason is that he is having early abnormal beats that were not picked up by the Holter monitor during the monitoring period.

It sounds as if he has been evaluated by a cardiologist, or at least has had a medical provider involved in his care since someone is ordering these tests.  I would recommend that he at least make sure that he is adequately hydrated, including having four 8-12 ounce glasses/day of fluid plus a salty snack, not skipping meals, and eliminating caffeine intake.  If he is still symptomatic despite these interventions, there are other monitors that can be used for intermittent symptoms called loop recorders.  Using one of these may be more helpful in specifically capturing these events at the time that they happen.