Apple announced the support of the electrocardiogram on the Apple Watch Series 4 for the end of the ‘year. According to a document distributed to the Apple Store, this will indeed be the case, so much so that the functionality will be proposed with watchOS 5.1.2 (currently in beta and which should soon be released in final version). According to the document consulted by MacRumors watchOS 5.1.2 will propose the application of the electrocardiogram which can indicate if the heart rhythm shows signs atrial fibrillation, a severe form of irregular heartbeat or normal sinus rhythm. The electrocardiogram is mainly proposed in the medical world today and not on the wrist with a connected watch.
Apple has already said that the electrocardiogram on the Apple Watch Series 4 will first be reserved for states -United. The manufacturer explains working with health organizations in different countries to offer his electrocardiogram to more people. As for the synchronization of the data, it takes place with the health application preinstalled on iOS. You must have an iPhone 5s minimum with iOS 12.1.1 at least to synchronize the data related to the electrocardiogram.
To perform an electrocardiogram, the user will only have to put his finger on the digital crown of the Apple Watch. The test is done in 30 seconds only. The Apple Watch Series 4 displays the results in the process to tell the user if everything is fine or if there is a problem.