DaveLeeNC

I ran into something odd yesterday (for reference it was on my 69th birthday). It was wet and cold so it was an indoor ride on my spinner bike (that has Garmin Vector pedals). I am not really training for anything these days and just ride like I feel. Yesterday started with a slow build from around 80% of ftp up to around 110% of ftp over a 30 minute period. That was enough of that, and the last 30 minutes was at a more casual pace in the 85% to 90% of ftp range.

My HR acted like you would expect in the first 30 minutes building steadily up to around 160 bpm at the end (my max HR is low 170's). After the first 30 minutes I spent a minute or so idly pedaling and finding the jazz guitar feed that I wanted to listen to, and spent the last 30 minutes pretty much in the 85 to 90% range and my HR leveled out at around 145'ish...

...EXCEPT for a short period in the middle where it bumped up to around 170 (in less than 10 seconds) and stayed about there for around 2 minutes before going back to the mid 140's where it belonged. Data is coming from a Garmin HR strap to a Garmin Edge 520. I have looked at it on Golden Cheetah as well as having dumped the data to a .csv file. Normally I would not think a thing about this as I have (on rare occasions) seen some far stranger HR stuff than this (like 240 bpm) that I am convinced is an equipment thing. And I felt totally normal. But this time I was wearing a Fitbit and it also was reading this oddly high HR #. So I am strongly inclined to believe that my data is real this time.

I have a annual physical scheduled in 5 weeks and am trying to decide if I need to address this before then (I have no history of heart issues, BTW). Again I want to emphasize that I felt just fine through the whole thing. Nothing like this has happened recently and I pretty much repeated yesterday's indoor ride today (another wet/cold day) without incident.

Comments here on creating an additional physician visit before my already scheduled appointment that has the purpose of investigating stuff like this?

dave

DaveLeeNC

Simply because pictures speak louder than words, here is a graph of 'the event' from Golden Cheetah. The red is HR and the Yellow is power. That spikey look to the power curve is because (even with a strong fan breeze in my face) I generate tons of sweat (literally from around my eye sockets) and each little dip is me wiping the sweat out of my eyes (like every 45 seconds or so). I wear glasses so that natural motion of taking the glasses off and wiping is associated with a 10 to 25% power output drop.

I will probably just wait for my appointment unless this reappears, but the picture is interesting. For scale purposes the width of the red 'event' is between 90 and 120 seconds. The bottom of the HR graph is around 147 bpm and the top is around 170. The grey/blue thing is cadence which is actually varying only a couple rpm.

dave

zacster

That's exactly what happens to me with my Garmin HR strap. It'll get stuck at a high or low HR and stay there for a few minutes then go back to normal. I had a reading of over 200 one day when I was just plodding along at an easy pace. Unless you actually feel your heart doing something out of the ordinary don't worry about it. It is just a problem with the strap. I've been thinking of replacing mine because of this and the fact that it takes about 10 minutes to connect. That's OK when I ride outside as it takes that long to get started, but indoors usually I'm on the bike and pedaling in a few minutes and I have to wait for the HR to connect.

The other thing mine does is that it will get stuck at an HR, then change and get stuck again. Look at the first part of the graph and how it is in steps and then at the 1.5 mile mark it starts looking normal.

DaveLeeNC

I have blamed my HR monitor or strap before when the readings were (temporarily) wildly off (like 240 bpm). But THIS TIME I had a separate monitor (a FITBIT which also monitors HR but does not use the Garmin strap). And it was also reading the same odd #'s as my Garmin and it does generally read the same #'s (roughly) as my Garmin. So in this case I believe the #'s (where in other cases I didn't but I also didn't have a 2nd HR monitor system in place).

BTW, I have never encountered a long connection delay with my Garmin strap and Edge device.

dave

pdlamb

It might be worth talking to your doctor about atrial fibrillation when you go in for your appointment. If you don't notice any symptoms (such as extreme fatigue or breathlessness), and the issue doesn't recur between now and then, I'd be tempted to let it ride (as it were).

Disclaimer: I have no competence in cardiology beyond a personal interest because of my own history. If you're looking to sue, take that information to your nearest emergency room immediately. You might even want to call an ambulance to take you there.

Carbonfiberboy 

Interference? I notice that your cadence and power slightly increased during the anomaly. Folks I've ridden with during an Afib event immediately noticed a drop in power, fatigue, etc. 2 minutes is a long time to be in Afib and not notice anything. If it's going to be an issue, it'll happen again. Stop immediately and try to figure out what's going on.

wphamilton

FWIW my HR readings spike until I'm warmed up and sweating, and I think it's due to picking up static until the sweating improves conductivity. Treadmill, I don't really monitor on the bike. If your chart is indicating that it stopped at around minute 16, that could be in the right time frame for a "slow build from around 80% of ftp"