Fig. 1.

Upper panel: Illustrations to show the recording of 30-second electrocardiographic tracings using Apple Watch. The watch was placed on the left wrist with the right index finger on the crown for recording lead I tracing, over the left lower abdomen for recording lead II tracing, and over the fifth intercostal space at the anterior axillary line for recording lead V5 tracing. Lower panel: Assessment of different T wave morphologies using Apple Watch electrocardiogram (awECG) and standard electrocardiogram (sECG).