Tachycardia, Anxiety, Enlarged Heart

I'm 50, and have been dealing with generalized anxiety and tachycardia for the last few years.  I've also been told, from chest x-ray, that my heart is at the high end of normal size.

I've been very sendentary since retiring early in 1999.  Basically I sit in my house and write or program or watch movies.  I know I'm very deconditioned and an trying to slowly start a walking program to regain my stamina.  After 4 weeks, I am up to walking for about 20 minutes a day, which still feels like work.  A big improvement over my first 5 minute walk, which left me winded.

This afternoon, as sometimes happens, I felt anxious after my walk.  My heart rate was about 100 bpm for hours.  Can that kind of elevated heart rate cause enlargement of the heart.

Specific questions are

1) what kinds of tests should I get to be sure I am not experiencing the beginnings of heart failure or some organic cause of tachycardia?

2) will building up to 30 or 40 minute walks daily help reduce the size of my heart and slow the rate?  

3) After years of inactivity, are we talking like 6 months or 12 months?  What should I expect if I am just dealing with deconditioning?

[Michael J. McWilliams, M.D.]

1) what kinds of tests should I get to be sure I am not experiencing the beginnings of heart failure or some organic cause of tachycardia?

It sounds more like deconditioning.  If you have been sedentary for that long, it is probably best to talk to your doctor about a stress test to make sure that you are ready to get fit again. It would be very rare for a tachycardia syndrome to have heart rates of 100.  That is pretty slow.

2) will building up to 30 or 40 minute walks daily help reduce the size of my heart and slow the rate?  

Xrays are not a very good way to assess heart size.  Echocardiograms are a much better test.  Again, it is probably best to meet with a cardiologist to help assess if further testing is necessary. You will likely need an echocardiogram and a stress test.

3) After years of inactivity, are we talking like 6 months or 12 months?  What should I expect if I am just dealing with deconditioning?

Like you mentioned above, you already feel better after just weeks of walking.  It will take you months to significantly improve your exercise tolerance.  It already sounds like you are on your way.  I applaud your efforts to improve your fitness and decrease your long term cardiovascular risk, but I would recommend seeing a doctor / cardiologist before you step your activity up too much.

I hope this answers your quesitons.  Thanks for posting.

[DPM111]

Many thanks Dr. McWilliams.

I did talk to my regular doctor, who listened to my heart and did an EKG, but not the more advanced tests you mentioned.

Three years ago I had a calcium CT, a 3D imaging of the heart.  It showed no signs of calcium build up in my coronary arteries, actually the said it was unusually clear for someone my age.  There was some calcium signs on the valves.