Under the likely heading of TL;DR...
Thought I'd share my experience on this journey.
I'm 66+ very active never took more than an occasional aspirin until I was 65 and then was diagnosed with stage 3 CKD. Bummer... Anyway because of my general good health my nephrologist convinced me to relax. The only change in my life at that time was now taking 12.5 mg of Hydrochlorothiazide every day. The initial dosage of 25 mg caused me to get light headed and faint often so he cut the dosage in half. (There will be a call back to this symptom as the story progresses.)
I regularly do vigorous cardio exercises. Typically spin and spin/sprint classes. ("Les Mills RPM") I always wear a chest EKG type HR monitor as I like to see and record the improvement (or otherwise) in my conditioning.
Since I started it typically looked like what you'd expect. Like this from December 26th, 2018.
Having retired we spend our winters in Mexico. This year we flew to the states for Christmas and I caught some bug that was kind of a gnarly upper chest congestion thing but nothing that I thought was too serious. (And don't have a clue if it had anything to do with what came later.) So being under the weather I didn't resume exercising until January 17th. I felt a little out of shape for having a couple of weeks off but nothing I hadn't experienced before after having taking some time off from exercise in the past. However my HR during spinning did a strange thing as shown at this link.
The next time I spun two days later it was doing more of the same. I initially thought my HR monitor was acting up but I confirmed the results by borrowing my wife's which produced the same result.
As the next few days passed the behavior got more and more pronounced until as seen below my HR dropped to around 70 bpm for the entire duration of the 45 minute work out. (This was on an elliptical machine.)
Here's the output of the elliptical machine.
It was about about this time I had got some metal flakes stuck in my eye so I went to an opthamologist and told him... "Hey, I'm 66 and was running (elliptical machine) with an average speed of 4.4 mph for 45 minutes and my HR average was only 72 bpm during the entire workout. What should I do?" He asked me if I got light headed and fell off the machine. I said No. He said, "Then if I were you I'd start running marathons!" (I thought that was funny.) He then said actually if this isn't a fluke with my monitor then you should see a cardiologist.
So cardiologist stories a bit later but from what I could see from the last HR graph was that my heart was mocking me! As can be seen as I start my exercise my hr goes up as expected and then violently drops to the low sixties. Doesn't ramp down slowly but drops like a rock like a switch is flipped to the low setting. (Thankfully not off.) I say violently but other than seeing it on my monitor I don't sense anything differently than before. I'm sweating like I always do which is a lot but generally feel exhilarated with the workout. The sudden drop I kinda get. Or at least could understand what might be happening there. What I don't get (and so far nobody's been able to explain it such that I could understand it) is what happens on the other end. That is within seconds of stopping the exercise my HR jumps back up to about where, at this point in my exercise, it would be had been had it not dropped. Then is starts lowering as I cool down as expected. It gets even weirder than this. When spinning between tracks there is a short rest. So 7 tracks then at least 6 short rests. (A rest means just pedaling easy between tracks for 10 seconds or so.) During these 'rests' my HR stays hovering in the low 70s but when I get off the bike (or elliptical) machine my HR, within a few seconds, rises back to where it should be. Like I said I think my heart if mocking me... Hey buddy if you are going to make me work I'll show you who's boss and then just to drive you crazy I'll start working properly as soon as you stop exercising.
So with pictures and charts in hand I search out and find what I had been told was the best cardiologist in PV. (Turns our she perhaps is!) On my first visit she did a 12 lead EKG and told me it appears that I have a "Right Bundle Branch Block." (I still can't say that three times fast.) She then wanted me back the following week to start a "Holter Test" explaining that we needed 3 days to catch the anomalies. I told her I could generate the behavior just by working out, that we didn't need 3 days but I complied. So I finished the test and got it back to her on a Friday. She told she would look at it over the weekend and set a follow up appointment for the following Friday. On Monday she called me and said please be here on Wednesday. So my wife and I went in and she showed us the Holter results. Bottom line was despite the fact that I had no sensations of fainting, lightheadedness or dizziness that I had a "Complete Right Bundle Branch/left anterior Hemiblock, AV dissociation (1st degree/2nd degree AV block)" Whatever all that was. She said that I needed a dual chamber pacemaker. Oh goody. (not!) She said protocol was that before that would take place I needed to have a echo stress test done. Not because I might not need a pacemaker but that was just "protocol" to insure it was a pure electrical issue and not a structural issue. So that echo/stress test was scheduled for the next week. She also advised me to stop the vigorous cardio exercise so I limited myself to yoga.
Just the next day we found out that we needed to fly home for a funeral so I decided to see if I could talk to a stateside cardiologist. Turns out not with that short notice but I could arrange a stateside echo/stress test and that's what I did.
I told the nurses exactly what would happen with my HR. (That it would drop after a exertion starts and then rise after I stop.) This was the first stress test I've ever done and in the end they had to tell me to stop because I went past some time limit. It was a nothing burger compared to the cardio I had been doing up to that point.
We flew back to Mexico and I contacted my stateside GP. This is what he replied with.
"I have the stress echo report from Cardiology--looks pretty good! You do have the right bundle branch block but there was no ischemia seen during this test and it was basically reasonably normal. There was one small area of fixed basal hypokinesis on the inferior part of your heart which could suggest a prior small heart attack but it does seem chronic and stable and there is no active restriction in your coronary artery circulation at this time seen on this test. So no I do not think you need to cancel your travel plans or restrict your cardio exercise and I do think it would be okay to follow-up with Cardiology at your convenience."
I forwarded this to my PV cardiologist and she replied. "But what did the Cardiologist say about the Holter report/findings? Did they not repeat it?"
I forwarded that to my GP and got this back.
"Our cardiologists have already reviewed your EKG and stress echo and honestly it doesn’t sound like they recommend any treatment at all so in reality you will probably require no treatment for these EKG abnormalities. I’m really not sure why you would even use the word ‘pacemaker’. I would just schedule an appointment with one of our cardiologists at some point in the future when it is convenient for you but in the meantime I don’t think you need any specific treatment."
So back in Mexico I started my rigerous cardio exercises again and life was good and I ignored my weird HR charts. Drove back to the states in April and continued exercising. In May the weather got warm/good enough to wakesurf (surfing behind a boat) and that did me in! Generally my high heart rate when spinning is 148-ish max. When I'm hitting surfing hard my heart rate is in the mid 160s. This spring while surfing I could only go for less than a minute and was then physically wiped out. In prior years I was used to 20 minutes sessions. So this wasn't good. Then I tried some other High Intensity Interval Training (HIIT) stuff and it all kicked my butt. While I was exhausted I still never got light headed or dizzy or anything. (Which now seems odd since I did get light headed and dizzy with that initial dosage of BP meds!)
I decided it was time to talk to another (now the third) cardiologist. (He got good Yelp reviews! :-) I went in with all my charts and stuff under my arm. (Actually I had sent it to him prior.) By now during exercise I was wearing an EKG chest strap HR monitor, my Samsung Galaxy Active Watch (optical sensing) and my Motiv HR tracking ring. (I'll likely do another post on my thoughts on all of these different HR recording devices.) That cardiologist joked that what I needed was yet another HR monitoring device. He said what I really needed was to see an electrophysiologist as from the stress/echo test my heart structurally wasn't in horrible shape but actually good shape. This was the first time I heard of an EP as my Mexico cardiologist was a one stop shop. She did it all.
So the next week I scheduled a visit with the recommended EP. Ten days later I was the proud owner of a St Jude's (Now Abbott) Assurity MRI pacemaker. That meeting with the EP was interesting. We met and I pulled out my charts and started rambling. (He already had most of the charts from my file.) At some point he stopped me and said "I know all of this I can tell you what I found from the charts. Your PV doctor was absolutely correct. I can see it all from the Holter results." His diagnosis was "Second degree type II AVB
Paroxysmal (sudden occurence of or increase in symptoms) complete heart block" During the procedure, heaven forbid you call it a surgery, (City Slickers Movie reference) my entire electrical system completely blocked for a time. Again I think it could be my heart mocking me! :-)
Anyway this long ramble just leads me to the question of how common is it that one can have these sort of issues and not even realize it unless you happen to be obsessive about recording your workouts? Every cardiologist, EP and device tech has been surprised that I haven't felt dizzy or faint. (Maybe I'm just always dizzy so can't tell the difference! :-)
That's enough for now. I may follow up with some of my observations regarding recovery and why if I had to do it all over again I think I'd have them implant the pacemaker in my thigh instead of just below my collar bone.
Anybody relate to this type of journey?