[savio marel oliver (OP)]

This question has puzzled me [] because humans do various activities such walking , running swimming etc requires a certain amount of heart beats per minute so how does an artificial  pacemaker know at what rhythm should it regulate the heart for higher efficiency for a heart patient ?

[JnA]

"The pacemaker's generator sends the electrical pulses that correct or set your heart rhythm. A computer chip figures out what types of electrical pulses to send to the heart and when those pulses are needed. To do this, the computer chip uses the information it receives from the wires connected to the heart. It also may use information from sensors in the wires that detect your movement, blood temperature, breathing, or other factors that indicate your level of physical activity. That way, it can make your heart beat faster when you exercise."

http://www.nhlbi.nih.gov/health/dci/Diseases/pace/pace_howdoes.html