HR completely screwed up while running or cycling
In December 2018, I had to have a pacemaker implanted. It is a Medtronic Azure XT SR MRI SureScan with a SINGLE lead into the lower chamber of my heart. (They could not put the second lead into the atrium due to small veins. My AV node is not working at all and so the important lead was to the lower chamber.)
I am a male, 52 years old and a recreational athlete...used to run 6 - 8 miles at a 11:30 min/mile pace 2 - 3 times a week. I also biked 50 miles at approx 16 mph once a week. Have also done a few Olympic and Sprint triathlons. I am 5' 8" tall and my weight was 156 lb before December...now it is 164 lbs.
Anyway, it's been six months now and I have been trying to run and bike but am seeing a few issues and was wondering if anyone has faced something like this before.
My resting HR is set to 70 bpm and the upper limit for the "Activities of Daily Living" setting is set to 120 bpm. The top limit of the "Exercise" setting is 155 bpm. I understand that the pacemaker will go into the Exercise mode once it detects running motion. The problem is that as soon as I start running, it goes to 155 immediately...I might not even have run 100 feet. There does not seem to be a gradual increase in HR as I start running slowly. The doctors have been playing with the setting to no avail yet. The best run I have had so far as been a 3 mile run at 13 min/mile pace.
My questions are:
- Can they somehow modify the pacemaker so that it gradually increases the HR?
- Should the upper limit of my Exercise setting be say 135 or 140 bpm? Because that was my comfort zone before the implant.
- Say, I wanted to sprint, will the pacemaker allow the HR to exceed the max setting for a few min or seconds?
- During one of the sessions, the lab technician who was changing the settings told me that this pacemaker gathers data and then modified its behavior. Not sure if anyone has any experience with this.
- When it comes to cycling, the problem is opposite. The pacemaker seems to be stuck at 120 bpm even though I need a little more juice. I understand that's because the pacemaker is not detecting upper body motion. What's the solution to this? I have tried to tap on it manually today but it seemed to make no change.
- Does anyone know what it will do to my swimming?
I wonder how the body regulates its HR in a normal person. Because of the pacemaker implant, is some sort of feedback loop now broken? Is the pulmonary function entirely dependent or independent on the HR? I guess I have forgotten my high school classes...
BTW, all data is collected on my Apple Watch 4.
Appreciate any help/thoughts anyone can provide. Thank you in advance...if there is additional information you need, let me know.