A:Answer Series 6 Apple watch has ECG (1 lead version). Cardiologist typically use a 12 lead measurements. A lead is the number of sensor place around the cardiac cavity to measure the heart functions. The apulse Oxygen measurements is new and interesting. It works very well. Many other health monitoring functions are available via Apps. The data can be captured and charted over the years. When I go for my annual physical, my doc get to review a year's worth of data.....BMI, Max exercise heart rates, blood pressure, etc..... professionally, I am a Data Scientist.