Apple Watch’s ECG feature to be US-exclusive

Shoppers queuing up to buy Apple's latest smartwatch anywhere but the US face an uncertain wait before they can use the product's headline-grabbing electrocardiogram feature.

Only American customers are being told the functionality will be enabled for them later this year. Apple isn't even promoting the feature on its international websites, and instead focuses solely on the existing heart rate analysis tool that was present in earlier models.

So far, only the US Food and Drug Administration has given clearance, sending the iPhone-maker confirmation on September 11 -- just one day before Apple Chief Executive Officer Tim Cook took to the stage at the company's headquarters to announce the product.

The process of gaining approval from international equivalents to the FDA are underway, according to a person familiar with the matter. No date has been set for a global roll-out, the person said, but they said the feature would be enabled via a software update when certification was granted.

Representatives for the European Medicines Agency and UK's Medicines and Healthcare Products Regulatory Agency didn't respond to requests for comment. A spokeswoman for Apple declined to comment.

The ECG capability of the Apple Watch helps the device sense atrial fibrillation, an irregular heart rate that can increase the risk of stroke, heart failure and other heart-related complications.

On Thursday, FDA Commissioner Scott Gottlieb said in an interview that the US regulator wants to make it easier for other companies to follow Apple's lead in integrating products like the Apple Watch's heart monitor into new consumer gadgets. "The door is open to any manufacturer," he said.