Odd heart rhythm and safety while exercising

[0606]

I really want to start going to the gym and taking fitness classes but I worry about safety risks after being diagnosed with respiratory sinus arrhythmia (still dont know what that really is).

Background info: I am a 22 year old female, 5'0 and 96 lbs. About a year ago I had heart palpations during a period of time when I was underweight (88lbs) and low in potassium due to gastro intestinal issues. I waited a long time for an appointment with a cardiologist and when I finally got one, the palpitations were better and I had gained most of the weight back. I had an EKG, an echo cardiogram, stress test and a holter monitor for about a week. The results of the echo were completely normal, however the EKG showed sinus bradycardia ( heart rate was 56 bpm) with marked sinus arrhythmia. The holter monitor showed that I have the sinus arrhythmia almost all the time. The average resting heart rate was still about 56. The cardiologist listened to my breathing and diagnosed "respiratory sinus arrhythmia".  Is this a safe rhythm? Will it make high intensity workouts less safe? He said the rate of 56 isnt dangerous because the ekg was otherwise normal. My boyfriend thinks the slow rate is a result of having a very short stature ( I doubt this is true).The stress test was mostly normal except for my pre-exercise blood pressure which was 84/53 which they thought was odd. However, I felt good and it rose to 127/51 at my maximal exertion level ( heart rate was 195). After 2 mins of stopping the stress test my heart rate dropped from 195 to 115 (seems elevated). Felt fine after but the odd rhythm still worries me.. All opinions welcome :)

[DeltaDawn23]

If your cardio has cleared you for exercise, it should be no problem.  When I first started exercising after my initial afib hospitalization, I was very nervous and worked out at the fitness center rehab section.  I now exercise at home, but it gave me the confidence I needed to get back to it.  Achillea's post sounds like you are in good shape!

[achillea]

Respiratory sinus arrhythmia is a variation in heart rate between inhaling and exhaling:  The heart rate slows a bit when exhaling, and increases a little when inhaling.

It is normal, and it is particularly noticeable in those who are young or very fit. It is a good thing to have, an indicator of how healthy you really are.

Here is more info:

http://jp.physoc.org/content/590/8/1989.short

If you're unsure, call the cardiologist for further explanation, but it sounds as though exercise is perfectly safe for you.