The proper placement of electrocardiogram (ECG or EKG) leads are the right arm, left arm, left leg and six different placements on the chest, notes the University of Utah. An EKG measures the electrical activity of the heart as waves to identify any problems.
An EKG has 12 different leads that are placed around the body to provide spatial information about the heart in three orthogonal directions, notes ECG Learning Center at Utah.edu. The directions are right to left, anterior to posterior and inferior to superior. There are three bipolar limb leads, three augmented unipolar limb leads and six unipolar chest leads. The leads are used to record the heart's electrical activity as tracings on paper.