Purpose: The M2A Capsule Endoscopy (Given Imaging, Ltd., Yoqneam, Israel) is a valuable tool for detecting small bowel disorders. The capsule transmits digital images to an external detector via radiofrequency energy (100–472 kHz). Approximately 2.4 mil Americans have implantable pacemakers, and 460,000 have implantable cardioverter defibrillators (ICDs), which also utilize radiofrequency energy (100–175 kHz) to communicate with programmers. Concerns about serious interactions between the M2A capsule and implantable pacemakers and defibrillators and potential interaction with radiofrequency overlap have been raised. We performed in-vitro experiments to determine the interactions between M2A capsule endoscopy and pacemakers and ICDs. Methods: We tested 3 current technology pacemaker pulse generators: models AT501 and KDR901 (Medtronic, Minneapolis, MN) and model 1296 Insignia (Guidant, St. Paul, MN); and 2 ICDs: model A155 Vitality AVT (Guidant) and model 7274 Marquis DR (Medtronic). Each of these was placed in an electrode gel bath along with the M2A capsule, while varying the distance of the capsule at 2, 6, 12, and 18 cm from the pacemakers and ICDs. We used a Virtual Interactive Patient model 9595 (Medtronic) to analyze pulse generator performance while simulating normal sinus rhythm. Atrial and ventricular electrograms and marker channels were observed for 30 seconds at each of the 4 distances and repeated in random sequence 3 times with the observer blinded to distance. This was repeated with the devices programmed to both nominal and most sensitive settings (0.15-2.8 mV). The pacemakers and ICDs were then attached to standard pacing and defibrillation leads, and the experiment was repeated at nominal and most sensitive settings. Results: All tracings were read in blinded fashion and in random order by a boarded cardiac electrophysiologist. There was no abnormal sensing on the atrial or ventricular electrograms or the marker channels in any device at any distance from the M2A capsule, even at the most sensitive programmable values. Similarly, there was no inappropriate pacemaker or ICD performance or spurious programming. Conclusions: Based on the extensive testing at variable distances of exposure and potential overlap of frequency, the M2A capsule endoscopy can be used safely with implantable cardiac rhythm control devices. Pacemakers and ICDs should no longer be considered exclusion criteria to patients who have need of this technology.