Aim: This study was designed to evaluate possible interactions between M2A video-capsule (Given Imaging System), a newest system of wireless endoscopy, and implanted pacemakers. Background: electromagnetic fields may interfere with normal pacemaker function. However the effects from the Given wireless endoscopy system remain unclear. Methods: The M2A video-capsule was tested in 100 consecutive patients with an implanted pacemaker (70M:30F). 95 pacemakers were on bipolar mode. The acute device testing was performed using the TestCap, a functional testing tool for the Given diagnostic system as it transmits exactly at the same frequency of the capsule. During continuous electrocardiographic recording, 100 tests were carried out at current settings and those with positive results were tested once again. Results: The 100 pacemakers evaluated in the population were as follows: 70 dual-chamber-11 DDD, 56 DDDR, 3 VDD and 30 ventricular-inhibited-12 VVI and 18 VVIR pacemakers; 39 Pacesetter, 32 Medtronic, 15 Guidant, 13 Biotronik and 1 Sorin. In 4 of 100 patients, a reproducible pacemaker interference was induced during TestCap operation. Three of them using a dual chamber (Affinity, Trilogy and Logos) and the remaining patient a single chamber (Actros). None of the implanted pacemakers tested were affected by oversensing. According with these results, Pacessetter's devices presented a 5% of interference and Biotronik's 15% (Odds ratio 3.3; p = 0.23). Conclusions: Interference of the M2A capsule with pacemakers was low and not clinically significant to our patients. There were no potentially dangerous pacemaker inhibitions. Our findings showed that the M2A video-capsule caused electromagnetic interference in only 4% of 100 patients tested. Aim: This study was designed to evaluate possible interactions between M2A video-capsule (Given Imaging System), a newest system of wireless endoscopy, and implanted pacemakers. Background: electromagnetic fields may interfere with normal pacemaker function. However the effects from the Given wireless endoscopy system remain unclear. Methods: The M2A video-capsule was tested in 100 consecutive patients with an implanted pacemaker (70M:30F). 95 pacemakers were on bipolar mode. The acute device testing was performed using the TestCap, a functional testing tool for the Given diagnostic system as it transmits exactly at the same frequency of the capsule. During continuous electrocardiographic recording, 100 tests were carried out at current settings and those with positive results were tested once again. Results: The 100 pacemakers evaluated in the population were as follows: 70 dual-chamber-11 DDD, 56 DDDR, 3 VDD and 30 ventricular-inhibited-12 VVI and 18 VVIR pacemakers; 39 Pacesetter, 32 Medtronic, 15 Guidant, 13 Biotronik and 1 Sorin. In 4 of 100 patients, a reproducible pacemaker interference was induced during TestCap operation. Three of them using a dual chamber (Affinity, Trilogy and Logos) and the remaining patient a single chamber (Actros). None of the implanted pacemakers tested were affected by oversensing. According with these results, Pacessetter's devices presented a 5% of interference and Biotronik's 15% (Odds ratio 3.3; p = 0.23). Conclusions: Interference of the M2A capsule with pacemakers was low and not clinically significant to our patients. There were no potentially dangerous pacemaker inhibitions. Our findings showed that the M2A video-capsule caused electromagnetic interference in only 4% of 100 patients tested.