There are no specific requirements if a medical device manufacturer wants to sell a medical device in New Zealand (the Director General and Minister of Health have some reserved powers but they are limited and blunt). Most manufacturers register their product voluntarily in the WAND database maintained by Medsafe.

There are plans to introduce a bill for regulating medical devices - was out for consultation last year.

https://www.health.govt.nz/our-work/regulation-health-and-disability-system/therapeutic-products-regulatory-regime

I have raised this issue (availability of ECG) with Apple directly last year, they understand the situation, the ball is in their court.

Jon