OP here. Many of you have helped out with the mRhythm Study we launched a couple of months ago: https://itunes.apple.com/us/app/cardiogram/id1000017994?ls=1&

OP here. Many of you have helped out with the mRhythm Study we launched a couple of months ago: https://itunes.apple.com/us/app/cardiogram/id1000017994?ls=1&mt=8 https://itunes.apple.com/us/app/cardiogram/id1000017994?ls=1... https://mRhythmstudy.org https://mRhythmstudy.org We're planning to start publishing some of the insights we're learning from the study, and we thought we'd kick off with a post on the foundations: * How normal rhythm varies and why an "irregular pulse" is actually normal
 * What optical heart rate sensors measure, and how they're different from the ECGs commonly used in hospitals.
 * An example of an "irregularly irregular" abnormal heart rhythm.
 * An example of a regular abnormal heart rhythm (atrial flutter)
 * An answer to one of the most common questions we hear, "Could Apple Watch detect heart attacks?" (Short answer: not yet.)
 If you have questions or things you're curious about for the next few posts... we'd love to hear your thoughts!