Micro heartrate Electrocardiography

Hi to everyone.

I would like to know if it's possible to make a chip that contains a electrocardiography, a bluethoot emitter, and a battery that lasts at least 3 years (it just activate when the heart rate is 0 and send info to make a call or sms to your phone) it should fit in a size of a dog chip.

Unlikely, whatever technique is used to measure heart rate, there is a significant amount of analogue electronics involved that would need to be on constantly. The most reliable way of monitoring the heart is still with a sensing system on the chest, the simplest being a chest strap with built in sensors. Other techniques use optical sensing, ear, finger, and now the wrist are commonly used, but they are not always reliable.
As you say, the transmitter side of things would only need to come on in the event of a failure, so that could be very low power. Look at the Nordic semiconductor site for example, they have a very low power transmitter designed to operate off a coin cell.
The key to a system such as this would be very high reliability, or it is obviously of no use what so ever.
Implantable dog chips are purely passive( no battery), they get power from the reader, and act as a transponder.
Cheers,
Richard