Hermes

Both my wife and I have experienced odd high HR readings that were bogus. What I do is take my pulse either at the wrist or in the neck. I use a 5 second time and multiply by 12. I used to do this when running and I did not have any HR monitor. If your HR is really 180, you will know when you take your pulse. That is going to be 3 beat per second. You can tell that easily without a timer.

I would assume it is a glitch but easily verifiable.

Carbonfiberboy 

Thing is, what we feel as our pulse is ventricular beats. "Bogus" would be equipment issues which can show numbers which had nothing to do with one's heart. Worrisome would be electrical activity which did not result in a ventricular beat such as A-fib, which can be dangerous. I never checked my wrist pulse when I have had ventricular tachycardia, so I don't know if that results in a noticeable pulse. That was also picked up by my HRM as it is also electrical activity and also dangerous. I've had vTach both when wired into a ECG and when viewing heart activity graphically on my phone. I've never had Afib but have ridden with friends during their Afib episodes.

MoAlpha

Electrical HRMs only pick up ventricular beats (the QRS complex on the ECG). Ventricular beats continue through AF. They are just no longer under normal control. I just looked it up and the survival rate after out of hospital “pulseless electrical activity” cardiac arrest is 2-5%, so you don’t want that.

McFlyRides

When the humidity is low and in cool temps my jersey can flap in the wind and cause crazy readings from my chest strap. It’s just static electricity confusing the sensor. I can tell my hr hasn’t really changed by how I feel, even when the monitor says I’m in a life or death sprint. If I hold my hand over my chest, the flapping stops and hr reading reruns to normal.

Carbonfiberboy 

The Afibbing riders I've been with definitely noticed their HRM giving readings maybe 40 beats over what was appropriate for their effort and possibly above their noted MHR. These are riders using standard 4 electrode chest straps with diagnosed and treated Afib. We'd stop and wait for their HRs to return to normal, then proceed at reduced effort, below the HR which triggered their Afib. Observed in the wild.

Are you saying that even during Afib, the ventricle is also firing at that extreme rate? If so, why did the riders feel faint?

MoAlpha

In AF the ventricle keeps contracting, otherwise there would be cardiac arrest and death. However, it is no longer under the control of the of the sinus node and is driven by ectopic activity from elsewhere in the atrium or associated structures.. The resulting ventricular rate is usually high, but can be “normal” or even slow. An abnormally high ventricular rate prevents the ventricle from filling completely and reduces cardiac output, sometimes drastically. That’s why people experiencing pathological tachycardia feel faint or collapse, or die.

The big danger in AF, however, is not from tachycardia, but from clot forming in the non-contracting atrium and causing strokes, etc.

Hermes

My mom has a-fib and takes Eliquis to prevent the blood clots. I train with another 70+ guy at the track who has a-fib. He takes drugs for the condition but races. He rode team pursuit with me a couple of years ago when Worlds was in LA.

What I do is monitor symptoms and if I would get any of the symptoms that are indicative of a heart problem, I would go to the emergency room and get checked out.

Carbonfiberboy 

Yes, thanks. I was always like, "Let's get an aid car here!" but they always said, "no, this will pass." and were always right, TG. HRM would say somewhere between 140 and 170.