Chronotropic Incompetence(CI) - Need pacemaker

I'm hoping to find someone here with similar experience/situation who received a PM and had his/her problems solved. I've read thro' several posts here but nothing fits exactly. I'm primarily looking for advice on whether a PM will help me.

My problem, after 4 years of testing and some missteps by docs along the way appears to be that my heart rate does not go up with exercise as it should. I get dizzy, never have passed out, if I start exerting at some point. It's getting worse. 4 years ago it took about 15 mts of running at 10 mt pace. Now it can start right away after running a few yards. Typically there are 3 stages. Stage 1 is the dizzy spell preceded by a clutching sensation in my throat (that could be PVC's) and then I have to stop. I have seen my rate as high as 140 before the dizziness. Stage 2 my rate can be 90-100 if I am walking briskly, I dare not go any faster. Stage 3 is after I stop, my rate goes down to 50-60 (my normal resting is low 80's). Stage 4 is recovery to normal after about 2 hours. Stage 5 hasn't happened lately but I can wake up in the middle of a night (again only on an exercise day) with actual brady - 40 and below, can't sleep because of the pounding, getting up and walking about mostly fixes it.

I've been told a pacemaker will help but haven't been assured that meds won't be necessary. The theory is that with a PM I can take the arrhythmia meds and not worsen things. I know I have sinus pauses and at one time when I went in to get a Holter during brady. they saw a junctional rhythm. I've had an ablation for an atrial flutter that was seen during pacing about 2 years ago.

Q: (1) docs can't tell me why if I have CI, my rate really goes down only after the load is removed (resting) (2) can my ablation have contributed or worsened existing problems (3)If I get a PM implanted how is it going to know that I've just stopped exercising, but my rate needs to be at,say, 120 because I am catching up for the oxygen deficit of 1 mts ago?(4)could there be anything else that is giving me this SOB and dizziness, other than a low rate, which may only be 10-20 beats lower than it should be(5)are PM's able to smoothly pace your heart according to load?

I'd like to run like I used to years ago. I need to fix my problem because I'm not exercising as I should because of the fatigue after. Then again I don't want to have to take meds in conjunction with the PM. I can get a good amount of exercise right now by brisk walking plus weights, but I'll never be able to run from a tsunami or a knife wielding mugger.

I'd like to hear from anyone who has been down this road. Thanks



by axg9504 - 2007-04-26 02:04:52

Some background: I used to run regularly in my late 30's (one marathon), then slacked off but stayed fit till 50. Then the weight started piling on. Repeated attempts at a comeback always seemed to run into a wall,there was no improvement after a certain point. So maybe this was brewing till one day on one of these 'combeback' attempts I started getting dizzy. Like you my first stress test did not go to the point of dizziness. It showed them that my heart rate was responding normally. I had to have a heart cath because of a false positive on the nuclear stress test. Then my interventional cardio (IC) was at a loss for a solution till I started researching my rate and found my rate went down. My IC wanted me to see an EP, unfortunately at the time my insurance restricted me to an idiot who diagnosed me as having afib based on a couple of event monitor tests. (later discounted by another EP who did the ablation). This first EP would not listen to my heart monitoring results. Said my problem was not brady but tachy. Thank god my IC did not agree with him and agreed with me that I didn't need coumadin.

Your post gives me hope and thank you for it. I'm just thrilled to hear from someone who's been through this.I've talked to many runners that I know to find out if they ever heard of anyone like me. What I see in common with your situation is that my heart does not like to vist a higher rate for very long. A year ago it would tolerate 130-150 for a few minutes now it might be a few seconds.

I just want to clarify a couple of things. Were you at the point where even mild exercise would drop your rate when you get dizzy? Do you get SOB too? What is your estimate about the number of beats that your PM is providing to avoid the dizziness. I see my rate at 90-100 after I get the SOB while I'm doing my brisk walk (beyond which I cannot go once I hit my first dizzy spell). So maybe 40 extra beats might let me do what I want. How does the PM know where to take you? Have you ever had prolonged bradycardia after the dizziness episode? Did your heart ever recover after exercise and then go back again into brady?

Finally what type of PM did you get ? Make/ model. Did you have one who specializes in it rather than an IC do it? Do you have any pain at the implant site and does it interfere in any way?

I myself would not feel self-conscious about a PM. I wear hearing aids so a PM is going to be a lot less obtrusive. Thanks again!

Hi again axg

by KarenLL - 2007-04-26 04:04:39've thrown me on a few of your terms. What is SOB? Answers to your questions: Yes, I did get to the point that fairly mild exercise was bring on dizzy spells. I would work out on a Precore at very low settings and withing 5-10 minutes it would happen. I really don't know how long my pacemaker works for me. I do know by watching my heartrate monitor that it is usually at about 5 minute intervals that I see it drop. Of course I am not watching it all the time so I am not really sure. It does take a few seconds each time to kick in. My heart rate will read 125- 50-50-50-120, something like that. It is a little weird watching and waiting for your heart to catch up! From what I understand the pacemaker will only go so high. I think my surgeon told me around 140 (which is not high enough for me). So if I take my heart rate up to 160 the pacemaker will come in at 140, which is still better than 80 which it was doing. They keep telling me it is going to take about 3 months to figure out what I can do. I may have to take beta blockers to keep my heartrate down when I exercise. I hope not.

Yes I have had the prolonged dizzy spells and my heart rate would stay low for a few minutes. I kept going to doctors that kept telling me I was fine so I would push through the first and second dizzy spells. I should not have done this...who knows what additional damage I did.

Everyone is different but yes, I so still have pain at the site. My biggest problem is that I don't have a lot of fatty tissue on my chest so there really wasn't any good place to put it. Mine is located high near my collarbone and everytime I move my left arm across my body it pushes into my collarbone. Sleeping is the worst because I sleep on my side. I wish I had known this before my surgery, I would have asked them to put it further to the left. I had a surgeon from Mass General Hospital in Boston put my pacemaker in. He specialized in people with problems with the electrical impulses of the heart. I have a Medtronic ADDRL101ID. I was not given any options. I never even thought to ask.

Once again, I hope this helps!

I think I'm someone like you!

by KarenLL - 2007-04-26 11:04:00

I felt like I was reading was happened to me reading your situation. Like you, mine started a little over 4 years ago. I was running a marathon, at the 7th mile I felt great, I hit the 8th mile mark and everything a heartbeat. I became very dizzy and disoriented. I kept running at a very slow pace but knew something was wrong. I went to a bunch of different doctors but was told I had a mitrovalue prolapse or just a murmer. I was brushed off. Finally I couldn't take it ( they were making me feel like I was crazy )and went to the head of cardiology at a local hospital and told him he needed to listen to me! He let me do a stress test MY way. (A stress test they give a 70 old is not very stressful for me. I'm 44 and I am very active and teach a weight lifting class). I was running along fine until my heart rate hit 140, then my heart rate dropped to 80. I kept running until I was very dizzy, then I lied down. My heart rate stayed at 80 for 2 minutes and then shot up to 125. Finally they believed me!
I recieved my pacemaker on March 23 of this year. I have been wearing a heart rate monitor when I walk and I am seeing my heart rate drop when I am only at about 100 bpm! It is very scary. It will drop to about 50 for a few seconds and then the PM kicks in and it jumps to 100. They have not determined if I need to take medication too to keep my heart rate lower. I have an appointment next week to figure that out. If you are like me the dizzy spells will happen earlier and earlier in your running. I have a very high heart rate to begin with, it would not be abnormal for me to be running or spinning when my heart rate was at 180 or 190 and feel good. They think this started with me when my heart rate was in the 180 (4 years ago) and now it is happening in the 100's. They think it might continue to drop lower. They really don't have all the answers.

I have really just started exercising but I don't get the dizzy spells or the fatigue anymore. So far my pacemaker seems to pretty smoothy kick in when i need it, but it does take a few seconds for the PM to realize that my lower chamber is not beating.

I hope this helped. I know how difficult it is to decide whether to get a PM or not. I struggled with it for months. I felt defective and as vain as it sounds I was very upset about having this "thing" in my chest that people can see. I work at a gym and thought my participants would be scared to have an instructor with a PM. I start back next week so I guess I will see their reaction.

I look back now and know i had to do it as much as I hate it. If my heart rate keeps falling like it is I would be in serious trouble without it! Best of luck to you.



by axg9504 - 2007-04-27 09:04:09

sob: shortness of breath. I didn't know any of these acronyms myself till I started surfing heart forums .

As I type I am having sob after getting home from a 30 mt workout at the gym 45 mts ago. If I run upstairs I will get sob, sitting still it's ok. My rate is probably around 60-70 now, it will go to 80-90 if I exert. In about an hour it will recover. It's always erratic before it comes back to normal. I have a Timex monitor and it is sometimes wrong. I have to swipe the band with water to be sure.

In my town (SC) we don't have an EP. I like my interventional cardio, he and I disagreed with some of the EP's I went to. I did go to an EP in Charlotte NC who did the EP study and the ablation in my right atrium. I don't think that was necessary but he saw an atrial flutter when he revved up my heart and zapped it. My problems had started before this so I can't blame it. Although I sometimes wonder whether my post-exercise problems are being exacerbated by it. But there you are with the same problems. All of the docs I have seen don't have patients like me.

I don't want to take any beta blockers. I've been there when the first EP I had treated me for afib. I tried Toprol, Rhythmol and flecainide and they were disatrous. Toprol was the worst. Crappy all day and made me more exercise intolerant. The meds were making my slow rate worse because they are designed to lower rates (Toprol was originally a bp med). The theory is that with a pacemaker I won't have that problem but I'm not walking around all day feeling like crap just so I can run a few miles.

It's puzzling that your PM once it starts pacing you at a higher rate, drops out now and then and let's your natural pacemaker dictate the rate.

I will have to postpone my decision to next year when I can arrange my insurance so I pay less (or nothing). I'm going to try to plod on till then. We are not doing any damage with the lower rate, I've been assured that. It's the fatigue that accompanies it.

karen (contd)

by axg9504 - 2007-04-27 09:04:48

EP: electrophysiologist like the doc you went to.

forgot to mention that my dizzy spells can be avoided by backing off. What happens to me is that I slowly start fading out, my legs get heavy, as long as I stop right then I'll slowly again recover and then sob starts. It's never lasted more than a minute .

If you go on beta blockers you may want to ask for something that acts short term to get you through your workouts. That's probably what they will give you.

You know you're wired when...

You have rhythm.

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