Summary of “Smartwatches Are Changing the Purpose of the EKG”

Continuous EKG monitoring, like that available in the latest Apple Watch, might seem like a small technological leap, putting what was once the sole purview of hospitals and doctor’s offices neatly around a consumer’s wrist.
Continuous EKG monitoring is a little different from other, more discrete medical information.
Because the various parts of the heart produce different shapes of electrical activity owing to their size and muscularity, the EKG can also detect which chambers are beating at what time, and whether these chambers are correctly synced up and beating effectively.
The larger a muscle is, the stronger its electrical impulses, so the size of an EKG wave can also indicate whether parts of the heart muscle are enlarged or dangerously thickened.
Areas of the heart getting less oxygen will show changes in their electrical conduction, and the 12-lead EKG provides real-time information: not just indicating whether a patient is having a heart attack, but also which coronary vessels are most likely blocked.
The 12-lead EKG can also detect the location of scarring left behind by prior, sometimes silent heart attacks.
An EKG tracing will clearly show an area of dead heart muscle no longer conducting electrical signals.
An EKG doesn’t capture the shape or function of the heart’s valves, nor can it diagnose precarious plaques in the coronary arteries that could signal heart attacks waiting to happen.

The orginal article.