An electro-mechanical activation probe obtains information pertaining to both myocardial electrical activity and myocardial mechanical activity at each of a plurality of locations relative to the myocardium of a heart chamber. For each location, the temporal difference between a feature of the electrical activity, such as the QRS complex of an IEGM, and a feature of the mechanical activity, such as the onset of myocardial contraction, is compared to obtain a mechanical activation delay. A stimulation electrode is then positioned at one of the locations based on the comparison. The electrode may be positioned at the location having the greatest mechanical activation delay. Other mechanical activity, such as contractual force, may be used in conjunction with the mechanical activation delay to determine the optimal electrode location.