Bradycardia - Indications for Pacemaker

I'm a 61 year old male,non smoker. 3 yrs ago I started having exercise induced dizziness. I have no structural problems (based on cath), an EP study resulted in the ablation in the right atrium for an atrial flutter, which showed up on pacing. I do have a PFO. I still have my problems with exercise. Currently my problems occur AFTER exercise, I am able to go through my routine (running/walking/weights for 30-45 minutes). My own observation with a Timex monitor is that my bpm falls at some point during exercise (50-60 sometimes 40) and stays that way sometimes for half an hour or an hour after exercise. The other day it took 12 hours to recover. I awoke at midnight with palpitations. I had an EKG done the next day and it showed a junctional rhythm with 40 bpm. No other problems. The doc put a Holter on me. I know that my heart recovered its normal bpm about an hour later based on taking my pulse. The next day the Holter readings showed that rhythm was no longer junctional. My bpm had dipped as low as 38 and I had pauses, the longest of which was 2.2 seconds measured during sleep. He says that I am technically a candidate for a pacemaker.Questions (1) Would you concur? (2) what is it about exercise that could lead to this bradycardia, I have no problems otherwise. Thanks a bunch.

[CCF-M.D.-BJ]

axg

thanks for the post.

(1) Would you concur?

Pacemaker placement is a difficult question to answer without fully reviewing your medical history. The answer is if your symptoms are definitely correlated to your bradycardia, then probably. However, a lot of people have a slow heart rate without symptoms. A lot of people also have slow slow heart rates and pauses at night,  mostly mediated by changes in vagal tone and do not need pacemakers. However, your heart rate should increase with activity and if it doesnt then I would start to think about why it didnt and if due to incompetance of your hearts conduction system to adequetly respond, I would start to consider it. I would also want to know more about whether you truly are having intermittant a fib.

Also, I would not place too much credance on heart rate monitors especially if you are having intermittant a fib as they are notoriously poor with a fib. The event or holter would be better to measure your heart rate.

2) Normally the heart rate increases to exercise. Certain parts of your hearts wiring may increase the rate but not trasmit them effectively to other parts during exercise causing a block of transmission.  I would have to see your rhythm ecgs during the episodes to comment on specifically why its happening in you.

good luck


(2) what is it about exercise that could lead to this bradycardia, I have no problems otherwise. Thanks a bunch.

[axg9504]

Note: I said 'palpitations' - I meant the conscious feeling of my heart beating, every beat. Also I have had two sets of event monitoring studies predominantly taken during exercise. The first limited set of 4 readings was interpreted as having some Afib (disputed by a second EP who looked at it). The second set of event mon. studies showed none, only irregular sinus rhythm with pauses and low rates (around 50). I have no physical symptoms at rest or normal activities..

[axg9504]

It's a confusing situation. I can walk a mile in 15 mts and then work out with weights and my heart rate seems to respond correctly. If I do some running with the walking and go to say 2 miles on the treadmill and then do weights after, my heart rate seems to go down. So it seems to depend on the load. Also I have gotten light-headedness when my heart rate monitor shows 80-90 as well as when it shows 40-50. As for Afib, I have worn a Lifestar AF express about 20 times during these sessions. It has triggered several times and I have pressed the button myself a few times at the end of my exercise routine where my monitor tells me that my bpm is low. It did not show Afib but did show low bpm (correlating to my monitor)and pauses in my heart rate. I think I am not going to investigate further and just stick with a routine I can tolerate. Thanks for the advice..