Excellent points. Artifact is indeed a tricky problem for EKGs, and the ziopatch is a great device. Generally, multiple leads are needed (ideally 6 or 12 leads) to accurately measure repolarization of the heart.

> That and the Apple Watch is on the wrist, which could introduce artifact to the ECG.

If patent filings are a guide[1], Apple are aware and have been investigating options for user-friendly additional sensors elsewhere on the body.

Whether it comes to market is another matter, of course.

[1] http://patft1.uspto.gov/netacgi/nph-Parser?patentnumber=1108...

Good points!