Biotronic CLS system

• by xc skater
• 2024-10-22 13:38:51
• Exercise & Sports
• 39 views
• 1 comments

Like 45% of endurance athletes I have an atriopathy. When I lay off the gas for long enough for my sympathetic drive to decrease sufficiently during a workout (coasting downhill on a bike, stopping at a traffic light, taking the skis off to cross the road and then putting them back on) I go into 2nd degree AV block. I feel the AV dyssynchrony as being completely gassed and unable to continue until the block resolves about 10 min later. I was given two options: exercise less or get a pacer. Easy choice. 

During the first week post implant my Biotronik CLS at factory settings paced me at 137 after I had my morning coffee and at 160 (lower rate limit set to 40) during a very easy bike ride. I had that function turned off and the lower rate limit set to 30 (my resting HR is 37). Everything was perfect. After a few months I had them turn the CLS function back on at the very lowest setting because I wanted to give the pacer the ability to "learn" how much chronotrpopic support I might need (I am relatively chronotropically incompetent). After a week I did an easy but scary downhill roller ski session and noticed being paced at 170. My pacer is not supposed to be able to AV pace me at faster than 150, so I was assuming that the terror of the steep downhill was making the pacer track my own sinus rate at 170. This happened 3 times during that workout and once was on an easy uphill, so no terror and no other reason to be that fast. The next day it AV paced me at 100 at rest for 5hours straight. Now I am wondering if I can really interpret the 170 episodes the day prior as my sinus node waking up after a 3 year slumber of if that isn't too much of a coincidence given the malfunction of the CLS system providing inappropriately fast AV pacing even on the very lowest setting. Has anyone else had a similar experience?