exercise with IST

[nursjeannie]

Im 32 years old and have IST.  I love to run and have recently started training for a 1/2 marathon.  My resting HR is around 100 and with any activity up to 130 and as soon as I pick up my feet to run my HR easily reaches 180.  My SOB becomes pretty severe at times but I am determined to continue on.  After about 45 min my breathing becomes better but my HR remains 180-190's.  My question is if it is safe to maintain this high heart rate for prolonged periods of time.  Since I have to run so slow (even at a slow jog my hr is 180) It will take me 2-3 hours to complete a 1/2 marathon.  This is something I really want to do. Just wanted to make sure it is safe to do so.  

[Cleveland Clinic]

Inappropriate sinus tachycardia is caused by an abnormal sinus node and its response to the autonomic nervous system, in that it is hypersensitive to the catecholamine surges and so the heart rate increases very rapidly. The ventricular response is partially protected by the av node but this structure in young people is generally able to allow impulses run to the ventricles at up to 210 bpm. The heart rate is a general measure of the work effort that an athlete is attaining, and there are in fact several heart zones in which people train with goal to obtain increases in aerobic capacity or slower simply to lose weight. Given your age your maximal heart rate is 220-32= 188. For the majority of the time your heart rate should be in the 150-167 bpm for simple endurance training and 167-175 for sudden explosive efforts ( running up hills). Going this fast for long periods may cause you to hit your lactate threshold and loose power while running. It is only dangerous if you feel chest pain or pressure, severe shortness of breath or un-interupted palpitations.

[jaksmom03]

hi do you think that smoking and being overweight can effect your heart rate? and here is a question that I cant seem to get answered about IST I had just heard of it called POTS..is that the same thing?  to have IST does your heart rate stay high mine goes high when I get up from sitting to about 140 but it comes right back down and stays in the 110s-120s while doing anything and stays between 80-99 while sitting somtimes going down into the 70's not sure what it is when Im sleeping. can I have IST if my rate comes down and it under 100 when resting? Im a little confused becuase there are so many issues that effect heart rate...i had an echo I have tricuspid and pulmonary valve regergitation. im still not sure if these two issues can effect my heart rate. any ideas?

[nursjeannie]

IST is inappropriate sinus tachycardia.  As mentioned my HR jumps sky high with minimal exertion.  I have a dysfunction of my sympathetic nervous system, it seems to be hypersensitive.  I have had an ECHO which was normal, no MVP or other valvle problems.  As for atenolol unfortunately it would lower my blood pressure too much(I have very low BP normally), although I may be willing to try a small dose if need be.  Ablation treatment is not ideal and has limited results for IST.  For the person with weight issues and smoking, you really need to drop the weight and stop smoking.  You will be suprised at how much better you will feel.

[kitcurious]

How long after you exercise does it take your HR to return to what is your "normal" ?
I rode my bike for a little over an hour this AM ( I do at least an hour, often two, 3 times a week and do aerobics the other days) and I got home this morning and a half hour later my HR was 125 and right now, in the afternoon, it's 99.

The delayed recovery time does not improve no matter how many months I  keep up my routine. I get short of breath with very little effort as well. I tried jogging and  was out of breath ( this is after months of consistent exercise cycling 3 hours or more per week and aerobics other other days) within moments.

I would think it would gradually improve, but it appears to have improved some days and slipped backwards on others even though I keep pretty much to the same exercise schedule.

I have mild MVP maybe that ..????.

I'll be interested to read the doc's response to your question.
Thanks for asking it.

[jaksmom03]

I have high heart rate like that they just put me on atenenolol which is a beta blocker, what is IST?
have you had an echo done? Im 27 and having problems with my heart rate, I want to start walking and then get to running but im scared with my heart rate so high. I am a smoker and over weight I had a baby in nov and want to get the weight off I have read that helps the heart rate there is also  procedure called ablation which is supposed to fix high heart rate but I dont know alot about it I am headed to clevland heart clinic on thursday to see what they can tell me.