Atrial Fibrillation

This morning, I was going to take a bike ride on the Wabash Trace. As I prepared, I checked my heart monitor. Problems getting a reading. When I could get a reading, it was high and erratic.
This has happened before on a ride. I have been just chalking it up to monitor battery, bad connection to the skin, and others. But the batteries have been replaced and reset the chest strap.
Recently, I started checking my heart rate before heading to the trail. Today, with the high, erratic heart rate, I decided to go the the ER. That would show if I have a physical problem or malfunctioning monitor.
The diagnosis - Atrial Fibrillation - Irregular Heart Beat.
According to the National Heart, Lung, and Blood Institute (part of the NIH)... "AF occurs when rapid, disorganized electrical signals in the heart’s two upper chambers, called the atria (AY-tree-uh), cause them to contract very fast and irregularly (this is called fibrillation). As a result, blood pools in the atria and isn’t pumped completely into the heart’s two lower chambers, called the ventricles (VEN-trih-kuls). When this happens, the heart’s upper and lower chambers don’t work together as they should." The heart diagram is from the NHLBI web site.
I am off the bicycle until I can see my cardiologist. :-(
Now - here is the important part. Had I not been using a heart monitor I would not know I have Atrial Fibrillation!. My problem is asymptomatic - I have no symptoms. No dizziness, short of breath, fainting, weakness, or chest pains.
Sure, a couple times I felt a little "out of sorts" riding up to Dumfries on the Trace when the monitor was not reading right. I thought it was because I did not eat right that evening. Most times all I did was take it easy a little when riding.
Now I know what caused the erratic readings - and a strong proponent of heart monitors. Trust your instruments - that's what they are there for. My monitor may have saved my life!