exercise and SVT

I am a healthy 57 yo female, 5' 10", 150 lbs and all my life I have had periods when I had tachycardia, usually in the morning when I wake up--going upstairs etc. Several years ago I began having short, spontaneous--but infrequent--bouts of tachycardia that made me briefly dizzy but that hasn't happened in the past couple of years.  When I'm really fit it seems to mostly disappear.

I exercise strenuously at least 5 days a week--both bicycling and swimming, typically an hour at a time, although one bike ride a week might be 35 miles in 2+ hours. My heart rate during peak effort is typically over 100% of my predicted maximum HR.  I noticed recently that while my heart rate came down rapidly when I stopped exercising, it never went back to normal, but stayed about 20 bpm above normal.  When I ride at  the rate mentioned above, I can still carry on a conversation and am not uncomfortable.

During a recent holter monitor test, I took a bike ride and as usual my heart rate got up in the 170's at times, and while it was at that rate I had a short run of tachycardia that took it up to 180.  My doctor says I have SNVT--to which I cannot find any references.

Is it possible that I just don't conform to the formula for predicted maximum hr, and this is normal for me?

My doctor prescribed bystolic at a low dose.  It has slowed my heart rate by about 20 bpm but I feel fine. My question is, do I really need to take this medication?  What would happen if I didn't?

[ireneo]

Perhaps it was NSVT? That would be short bursts of v-tach. I admire your ability to exercise so vigorously. With my tachy I've never been able to do that. My heart rate will jump from 140 (during exercise) to almost 200. Doesn't feel very good and I have to stop till my heart settles down again.

Anyway, look up NSVT. In short little bursts in a healthy heart, it's not terribly dangerous. If you had longer runs, the cardio would have discussed different treatment options with you.

[raeve]

Hey there, hope this might be of some assistance to you. I had suffered from frequent and quite violent bouts of SVT since the age of 13, i'm 40 now. Started when I used to stay at my auntys place in NZ and continued for all my adult life until I found a cure for it only a few years ago. Hit me out of the blue really, my aunty was a diabetic and never had sugar in the house, only sugar supplements. As a result of that I got into the habit of thinking sugar was bad and started using the supplements from then on, as did the rest of my family. These supp's contained ASPARTAME. And once I got rid of anything that contained aspartame or phenalynine my SVT went away, completely. Used to get it 5-10 times a week for up to an hour at a time, have had only about 5 or 6 short episodes in the last year !! Also, eat smaller meals more frequently, stay hydrated, and GET RID OF ASPARTAME AND PHENALYNINE ! Aspartame is also known by the number 951 and is an artificial sweetener. Hope this helps you :)