An apparatus and method for detecting micro-dislodgment at a heart tissue/pacing lead electrode interface involves measuring a first pacing threshold parameter at a first time in a patient's cardiac cycle and measuring a second pacing threshold parameter at a second time in the patient's cardiac cycle. Micro-dislodgment occurring at the heart tissue/pacing lead electrode interface is detected using the first and second pacing threshold parameters. Micro-dislodgment may be detected by comparing a difference between, or a ratio of, the first and second pacing threshold parameters to a preestablished maximum allowable deviation value. A difference between the first and second pacing threshold parameters or a ratio in excess of the preestablished maximum allowable deviation value indicates a problem at the heart tissue/pacing lead interface. The first and second pacing threshold parameters are preferably pacing threshold voltages, and the preestablished maximum allowable deviation value is either a voltage ranging from about 0.2 volts to about 2 volts or a percentage ranging from about 5% to about 100%. The micro-dislodgment procedure may be performed in-situ an implantable pulse generator (IPG), with data indicative of a detected change at the heart tissue/pacing electrode interface being stored in a memory coupled to the IPG and subsequently read out of memory for evaluation. Alternatively, the micro-dislodgment procedure may be performed using an external programmer and may further be performed during implantation of a pacing lead electrode at the heart tissue/pacing lead electrode interface to assure a physician of proper lead attachment.