Walmart has massively marked down a highly-rated pulse oximeter that's designed to monitor ... my heart rate was acting crazy and I ended up in the ER in A Fib and spent 4 days in the hospital ...

But the best heart rate monitors aren't all created equal. For cyclists, the most popular are chest strap heart rate monitors, which, at their most basic, need to capture your beats per minute ...

Unlike getting an ECG at the hospital, you can monitor your heart throughout the day. “Irregularities in heart rate can be episodic, and difficult to capture,” explains Dr. Grimes ...