Slow Heart Arrhythmia

  I had an EPS done in 1990 for SVT at University of Michigan Med. Center.  The procedure was successful.  Five years later though my heart rate has gone just the opposite and slowed to around 36-45 beats per minute.  I saw a cardiologist where I currently live and he put me on Tambocor (50 mg) for awhile but I later discontinued using it due to side effects.  On a visit back to Michigan I saw the physician who did the EPS and he prescribed 50 mg of Atenolol but that seemed to worsen the heart rate so I stopped taking that also.  The only medication I am currently taking is Synthroid (.75 mg), and Premarin (.065 mg),  Our family physician increased the amount of my Synthroid from .50 mg to .75 mg. a couple of months ago and my heart rate was normal (60-75 bpm) for those couple of months until about two weeks ago when it slowed down again. I am wondering if this slow heart rate is a long-term side effect of the ablation or if it is something else.  I have had EKG's, ECG's, and Holter monitors and nothing unusual other than a premature heart beat has been found.  I am wondering if a pacemaker would be a viable option. Thank you for any information you can provide.    
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Dear Linda:
For people who are symptomatic from a slow heart rate, a pacemaker is a very useful form of therapy.  Also, for people that need to take certain heart medications that slow down the heart rate as a side effect, pacemakers can be wonderful.  For people that have low heart rates due to something like an underactive thyroid, the best course of action is to treat the hypothyroidism.  If someone has a low heart rate, but has no symptoms, and is otherwise healthy, the best course of action may be to do nothing.
Ablations can cause slow heart rates requiring a pacemaker, but that should become apparent soon after the procedure, not years later.  Heart medications like atenolol can also cause slow heart rates.  In general, only if the slow heart rate is causing symptoms should it be treated.    
If you wish to be evaluated here at the Cleveland Clinic, please call 1-800-CCF-CARE for an appointment with a  cardiologist who specializes in pacemakers at Desk F15.  Information provided in the Heart Forum is for general purposes only.  Specific diagnoses and therapies can only be provided by your doctor.