AV block, Medtronic Azure, Max HR question

Asymptomatic Bradycardia

by thesteven619 - 2020-07-15 16:37:27

Sorry, one more note.  The reason I got the PM was to eliminate the risk of my bradycardia becoming symptomatic.  My resting hr was consistenly dropping over the years, from about 45 when I was younger to about 35 now.  No history of afib, or any other known issues.  I have succesfully done plenty of treadmill tests showing my hr naturally rising up to 130bpm, in addition to hundreds (thousands?) of bike rides with my hr sitting above 100, though it has been a few years since I have done a treadmill test in an office setting.

Heart rate

by Dh13 - 2020-07-15 17:06:56

Im 58 and have had my PM for about 9 months.  I started with 60 to 130 rate.  60 seems like the normal low end.  

my top was increased to 140 then 150 and now 160.  My issue is that my heart rate would drop during excercise.  When I was at 130 running was a struggle and any small hill would be very difficult.  I am sure they are being conservative.  As soon as you go in for you first vist it can be adjusted.  I am sure it is frustrating.  There are also other sensitivity settings changes that can be made.  I still a newbie.  Others on here may have lots of info for you.  

There is some logic in keeping your HR down while the new leads bed in

by crustyg - 2020-07-15 18:46:01

Behind all the stuff about not raising your elbow above your shoulder on the side where the leads enter the big veins that give access to your heart (the idea being that as you stretch your arm you also pull the vein away from the heart and this pulls the leads away from the heart) is the other facet, which is easily overlooked.

Each heartbeat causes the newly installed leads to flex as the heart muscle contracts and moves.  The faster your heart beats, the more the leads wiggle around.  It does seem pretty common for newly installed PMs to be set at something like 60-130bpm while the new leads are slowly anchored in with fibrous tissue around the lead tip.

I would expect you to be able to get your PM adjusted to something more appropriate for an athletic lifestyle about 4-6weeks post implant.  For me that was 50-130 => 50-160bpm.  Seven months later I had my upper limit tweaked to 165bpm (gasp!).  At implantation my unassisted resting HR was about 40bpm, but I felt faint after climbing a single flight of stairs, so 50bpm seemed reasonable as a LRL.

Unless your EP doc works for a pro cycling team it's unlikely that (s)he has more than one or two keen cyclists on the books, and despite all that book learning, most docs don't really know what is an appropriate maxHR for a very fit 36year old athlete, let alone one in their 60s.  I got my 30+year old son to wear my chest strap on a ride we did together, so that we could see his HR on the last hill of the ride.  I think he topped out at about 172bpm: the athletic heart *tends* to get bigger and not that much faster - much better for the heart muscle and still delivers a lot of oxygenated blood to those big muscles.  I've asked around my cycling chums (40s and 50s) and very few of them reach a maxHR of >175bpm.

It certainly helps to justify a higher maxHR if you have had a 12-lead ECG done at something like that - your doc can see that there are no signs of ischaemia, or perhaps you've had a Bruce protocol treadmill test (continuous ECG) or a static bike session.  What they are terrified of is giving you a maxHR that takes you into heart attack territory - blood only flows in the coronary arteries during diastole - when the heart muscle is relaxed - and the need for coronary blood flow increases as HR increases.  So there's a vicious circle developing somewhere beyond 170-190bpm (usually) where heart muscle oxygen requirements cannot be met because the heart is beating too fast for the blood supply to deliver it.

I think you should just ask for a maxHR of 160bpm (suggest you don't ask for too much below 50bpm - a lot of the PM programming machines really object below 45 or 50bpm).  I *suspect* that if you ask for 180bpm it will be rejected immediately, 170 perhaps less likely, 160 should be an easy ask.  Point out that your heart *muscle* is healthy, you have no signs or symptoms of ischaemic heart disease (==your coronary arteries are clear), you have a sensible cholesterol level and you have been exercising at the level of a Bruce protocol test every time you go out on your bike.  Maximum charm!

HTH.

Doc not listening

by AgentX86 - 2020-07-15 18:49:38

Your doctor is very likely listening to you and then doing what's best.  He probably wants to take things slowly at first (a verygood idea). The difference in resting pace and exercising pace isn't very meaningful. Resting is resting and, well, exercising is exercising. If your heart didn't need mire than 135 before, you should be good now, for at least a while. Remember, these settings are meant to be dialed into your needs, lifestyle, and of course safety.

You have a long way to go to get things optimized for you. Yes, your doctor should have communicated better but you really need to do your research so that you can talk at his level. You're much more likely to get what you want if you can communicate.

Meanwhile take it easy and recover. Your life hasn't been limited in any meaningful way.

Communication...

by ShanaBer - 2020-07-16 22:31:16

I think the communication failure is a big issue and so frustrating. I did not have a chance to get my questions answered before or immediately after the implant and felt horrible for 2 weeks until my scheduled check up appointment. The PM tech was very helpful and explained that they usually leave the settings at the default (60 and 130 for pace along with many of the other settings) for the 1st 2 weeks at least. Once you see them for your check up you can talk to them about the pacing levels and other settings. My resting HR was in the mid to low 30's and my max HR ever, when running, was around 145 but had dropped considerably over the years to mostly be in the 120s despite what I tried. My max is set at 140 for now and can be adjusted later when I am running again if needed. However that pacing level is not a limit, if your heart wants to go higher it can, your PM just won't be pushing it higher.