Long Time Out Door Road Cyclist Now an Indoor Spin Cyclist

76yo with Cardiac Ablation in April '23 for Afib, now resolved post abalation. PM placment in July '23 secondary to SSS and worsening 2nd Degree AVB. I have a Boston Scietific L331, Accolade MRI. Current Parameter Settings: DDR, Lower rate 40, Mode Switch 170, Tracking Rate 135, Sensor Rate 135, Sensed AV 80, Paced AV 80, RightRate minute ventilation sensor on. These are setting the Boston Scientifc rep, a cyclist himself, tuned up the PM over 3 visits post placmen. 

Because of my complaints involving early fatige during spin events, I've had a cardio-pulmonary stationary bike test (got to 130% of predicted VO2 Max) and an Echo with normal result (EF 55-60%.) All of this suggests I'm doing fine with the current settings. Both my EPP and Cardiologist give off body language that I worry too much about the PM and that my PM settings are where they should be. Leave us alone.

I wear a polar HR sensor and a Polar watch. I can usually feel when pacing begins and ends and I can see it with Polar Flow analysis on my PC post spinning. HRV gets really high once I get HR >100. I can see this on my polar watch display. Sometimes I pace, sometimes I don't and it's an entirely intrinsic HR (e,g, when doing the VO2 Max study I got to max HR 135 in under 30 minutes) without pacing). PolarFlow analysis shows my HR increasing smoothly (sometimes intrinsic, sometimes V paced) at start of excercise where it tops out at 135, stays there for 30 seconds or so, then abruptly drops to <100 (I think this is 2:1 or greater Heart block kicking in and the PM isn't pickinig this up and so, is unpaced). This dance repeats itself for the duration of the spin class (45m to 1h). I do feel early muscle and respiratory fatigue in some spin classes, not all, which leads me to beleive condtioningis also at play here. I'm spinning 3-5X per week.If I miss a couple of spin classes, I know that fatigue is training related or lack there-of.

What can I do with my PM settings to get the PM to V pace over the heart block. I'd like it to pace based on the first indication that a V beat is blocked (that should look to the PM like a brady HR and jump in to pace. Seems to me it's not doing that consistently. Thoughts ????

4 Comments

Suggestions

by crustyg - 2024-09-28 02:15:51

Firstly I think 135BPM is much too low as a maxHR for you, but that's probably not the main cause of your early fatigue.

I see we discussed this exact issue a year ago...

You don't explicitly describe your pacing mode (sounds like AAIR), nor mention having had a Holter and exercising with it on: it sounds as you though are developing intermittent HB, in which case your pacing mode needs to be changed.  BostonSci offer a mode that is still basically AAIR but it will switch to DDIR (the docs all say it's DDDR but I am checking  if that's a documentation error, as DDDR for those with junctional rhythm that goes to a high rate would be at risk if it's not DDIR) when it detects HB.  If they enable AV Search+ make sure that the Search Interval is 32 cycles.  Basically I think you need RYTHMIQ to be set up for you.

Your BostonSci rep sounds good: I think you need to charm your EP-doc into another tuning/adjustment session, perhaps after a Holter has demonstrated exercise-induced HB.

Spinning with a PM

by jbuch002 - 2024-10-10 16:45:29

I'm responding to crustyg. Thanks for your response. Some additional background: I complained about early fatigue in a f/u visit with my Cardiologist (not my EP Cardiologist) in late June. He ordered a cardio-pulmonary workup that involved a stationary bike and ECG monitored VO2 Max testing. I achieved 130% of predicted VO2 max for my age and was told that there was no pacing/no indications of a heart block on the ECG during the test except a few skipped beats as I cooled down after the testing. I also had a color flow doppler done with visually estimated EF of 55-60%. So, he concludes, "your fine, stop worrying about it." Since then any concerns I express about my PM are dismissed including a request for a f/u visit with the Boston Scientifc rep. I had a Holter a year ago prior to PM placement that revealed several bradycardic events (< 30bpm) secondary to 2nd degree AV Block with 2:1 conduction (I've also demonstrated 3:1 and higher blocks). In addition to the heart block, I've also ben diagnosed with SSS. Historically, all of this is intermittent and the VO2 Max cardio-pulmonary results being normal prove that in the eyes of my doctors. I'm NOT imagining early fatigue when I spin. I don't think it is under training and conditioning related. I'm also not imagining the appearance on my Polar HRM of my PM not picking up and pacing where I would expect it to pace (in the presence of a block). I've expressed that to my EP doctor. He dismisses the value of HRMs as a diagnostic tool in general because of potential for intermittent loss of skin contact. You asked about my PM pacing mode. It is DDDR now. Was AAIR out of the box and that was changed to DDDR, RhythmIQ off at subsequent post placment follow-ups. The max HR is set at 135 bpm; it was 140 but when the paced and sensed AV delay was set to 80-350ms, with PVARP set to 250-300ms and VRP set to 250ms, that dictated lowering the max HR to 135 I was told (I'm not knowledgeable about the relationship among the AV delay, PVARP and VRP settings to max HR). I'm prepared to get a 2nd opinion but I'm not sure that would be productive. These guys all talk to each other.   

Just a tip

by Gemita - 2024-10-11 02:47:32

JBuch002,

Crustyg may not see your response since your original post was several weeks ago and the system here does not automatically bump late replies to the top of the message board where it would be seen.  It might be an idea to start a new message or to copy and paste your response to Crustyg in a new Private Message?

I know all these guys talk to each other but if confidence has broken down or you are getting no-where with this, I would consider getting a second opinion.  I got no-where with my first EP, but I pushed and pushed for answers and finally got referred to another colleague in the same centre and what a difference it made to the management of my care.

I see you have a history of AF and have had an ablation, so it is possible that you are still getting rhythm disturbances and these could be contributing to your difficulties.  I don't think you have had a recent long term external Holter or Event monitor (or Zio Patch) and I would request one for at least 7-10 days to help pick up any intermittent disturbances.  

I understand your frustrations, but do push for more answers/evidence of what is happening when you are symptomatic.  

Response to Gemita

by jbuch002 - 2024-10-11 11:32:08

Thanks for jumping in on this. You are correct in observing I'm "not getting anywhere" with my current EP or Cardiologist who seem dismissive of my concerns about my PM settings. I'm really not sure I know where "anywhere" is. I think its a ride where I get consistent pacing - and that doesn't seem to be happening. My Docs refer to the normal results of my VO2 max study and the normal cardiac US to argue, "everything is fine with your PM. Stop worrying about it." I've found a couple of good explanations on the web wrt to setting pacing modes. The process is complicated. As close as I can tell my DDDR pacing mode setting is the correct one for my cardiac abnormalities - sinus node dysfunction and 2nd degree AVB. Yes, I've had an ablation in June, 2023 after the PM placement. Since placement the PM has not recorded any AF. I'm experiencing a lot of PVCs (recorded) and PACs (not recorded) and can feel these. Their occurence is, IMO, related. My EP is unconcerned about these. I think the PVCs are messing with the PMs sensing and pacing functions and proper programing can correct that. When I inquired about reducing these PVC/PAC events, he said, "it's like whack-a-mole" implying that additional ablation of sites in the atrium - the source of ectopic beats - isn't indicated. I'm OK with that as long as we can get the settings on my PM to deal with them (ignore them) such that the PM will consistently recognize ectopic beats (PACs) and AV-blocks and pace over them. During cycling, the PM seems to start to pace but then stops and restarts periodically. I believe getting the PM programmed correctly (Paced and sensed AV Delay, PVARP, VRP is the solution but, what do I know.

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