Electrocardiogram (ECG) measurement on a wrist-worn electronic device

An electronic device worn, such as a wrist-worn watch, able to generate and display an ECG image associated with the wearer's heart. The device includes electrically-conductive first and second contact points for conveying first and second signals. The first contact point is located on a bezel or a pushbutton of the electronic device that is physically touchable by the wearer. The second contact point is located on the bottom of the housing so as to physically contact the wearer's skin of the user's wrist when the device is worn. The electronic device may also receive location signals to determine a current location using an antenna at least partially formed by the bezel. A processing element may receive the first and second signals, generate an ECG waveform, and an ECG image based thereon. A display graphically presents the ECG image as a sequence or stream of ECG images.