A non-tissue contacting electrode system senses physiologic signals from a patient during implant and/or followup of an implantable medical device (IMD) via an external programmer or other monitoring instrument. These sensing systems are electrically connected to the circuitry of the external device and detect cardiac depolarization waveforms displayable as electrocardiographic tracings on the instrument screen when the programming head is positioned above an implanted pacemaker (or other implanted device) so equipped with a non-tissue contacting electrode system. The structure and system provide an enhanced capability for detecting and gathering physiological signals from a patient with minimally invasive patient contact.