What could be causing the tachycardia

[rockchalk76]

I am a 53 yr. female, who started experiencing continual pulse rates of 100+.  After having a family doctor that wrote this off to "white coat syndrome", I switched to an internist.  She 1st placed me on Atenolol 50 mg, which I could not tolerate, & even reducing it to 25 mg I could not sleep, had asthmatic problems, & Raynoud's syndrome.  My BP was usually either normal or prehypertensive range for the last two years.  I am 5'9" & 185 lbs. I exercise by walking my dog 2 miles a day & do weight lifting at least once a week. I am now on Diltiazem 240 mg.  The internist increased it from 120 mg, when I was having spikes of 140/90 with BP.  It appears that the higher dosage is now controlling the BP (this morning it was 110/69) but not necessarily the pulse rate (was up to 99 yesterday afternoon).  I am on a 30 day cardiac monitor that was started on 1/23/08.  I had one ''event" of pulse of 120 that went back to high 90's after an hour.  My cholesterol was 225, trigylycerides in normal range, with LDL of 159 & HDL of 49. I do not have a family history of any heart disease.  I do not smoke & never have.  I have one glass of red wine a day.  Because my husband developed high BP & then A-fib, we have been eating a low fat, high fiber diet for over a year. I had rheumatic fever as a child, but doctors have not heard a heart murmur for years.  Up until now I have been very healthy all of my adult life. I have a B.S. in medical technology.  As  scientist, I am not satisfied with just taking medicine.  I really want to understand the WHY!  My internist says that if the Diltiazem is not controlling my tachycardia by the end of this week, she will refer me to a cardiologist.  She said that she doesn't have as many drugs to work with, with a high pulse rate as she does with someone who just has high BP.  We have good insurance so can having any testing that is required, but I would prefer not to get into anything invasive until we have exhausted the non-invasive options.  

[Cleveland Clinic]

The first question you have to answer is what is the rhythm for this tachycardia: is this sinus rhythm or not. If not and you have these symptoms and the medication is not controlling it then you may need to undergo an EPS where the inside electrical network of the heart is studied and is almost 100% effective in diagnosing the electrical arrhythmia, and usually almost as effective in treating it. You want to know why, but in many instances that question cannot be answered: we know it does happen and it causes symptoms and that we can treat it.
If the rhythm is sinus tachycardia then is may be secondary to thyroid disease,deconditioning or inappropriate sinus tachycardia. All of these have different causes and are treated differently. The last of these ( inappropriate sinus tachycardia or IST) is something it has been addressed here in the forums many times, and is usually treated by medications such as diltiazem or via an EP study with RF ablation.I

[MAB22]

I have been placed on Atenolol 25 mg per day for sinus tachycardia.  I wish I had never started the stuff, as I feel worse now than when I started on it.  I think the cardiologist overreacted too.  I wasn't in any discomfort from tachycardia and not really aware of problems with.  I am 5'8", 189 lbs, 43 yo male.  My cholesterol is around 230.  They didn't tell me why I had tachy, just jumped to beta blocker.  It has been 7 months since I have been on and my blood pressure is going up (funny since BB is for treating Hypertension).  This drug depresses heart function and has depressed mine.  I see my cardiologist in july 2008.  Right now I am trying to lose weight and exercise.  Hopefully I can bring down BP and HR.  Maybe fast heart rate is from deconditioning and elevated cholesterol.  I am trying to bring my cholesterol to within normal limits.  I also have a sedentary job, and this further contributes to my deconditioning.  I wish I knew why I have this tachycardia.  Hope things get better.

[rockchalk76]

I feel a sudden exhaustion when the pulse rate goes up.  I had been in my basement working on a quilt when it hit the first time and my heart rate went up to 120.  The second time, I was sitting at my computer reading an email from a friend - in otherwords, neither time was I doing anything stressful.  This never occurred before I was put on BP meds; I just had a heart rate of around 90 - 100.  It has been very tempting to just go off of them and see if I can't do it with diet and exercise, now that I know I have this problem.  I turned down a new job today, because I didn't think it was the time to add any stress.  I now work as a librarian and have been reading books on hypertension and heart disease.  I am really wondering why the internist put me on a Beta Blocker at a higher dose, right off the bat, instead of trying me on the calcium channel blocker that I am now using which has almost no side effects.  What I am reading indicates that a Beta Blocker would be a third or fourth choice in my situation.  I was a researcher in veterinary medicine for a number of years and have had veterinary pharmacology.  If an animal was not in crisis (and putting myself in that category,  I don't believe I was) you start them on a low dose and progress to a higher dose if that does not fix or lessen the problem.  You also start them with the most conservative of treatments, since I wasn't sitting in an emergency room with symptoms of heart attack. I'm feeling that the internist went too far the other direction from my family doctor: no treatment to over treatment!  Are my fears correct?

My internist did the usual and had her nurse call and tell me, "Everything was fine but..."  I'm not even sure that they ran a T3 and T4.  They did some thyroid test but don't know which one; I was told that the thyroid test was normal.  From now on I will insist on a copy of the results.  As a med tech, I know what the tests mean.  I was suffering from the unexpected news that I had any kind of a problem and didn't act as I should have.  Thanks, Kay

[maggiemag]

Make sure they test your thyroid levels with a TSH, free T4 and free T3.

[crazy4cardio]

Hello, I'm sorry about your tachycardia.  I have random bouts of it myself, but it seems more set off my things which raise the adreneline levels, and no one can tell me why either.    Do you experiece the sensation of lightheadedness, near fainting, or heightened anxiety when your pulse is high?