Effects of capsule endoscopy on cardiac pacemakers

Background and Study Aims: Capsule endoscopy is a new, noninvasive diagnostic technique which enables visualization of the mucosa of the small intestine in physiological conditions and without the need to subject the patient to external radiation. Wireless capsule video endoscopy is contraindicated in patients with a cardiac pacemaker. However, on the basis of the characteristics of the radiofrequency band used by the endoscopic capsule, together with a series of other factors, it is possible that the patient's use of a pacemaker should not be a contraindication to capsule endoscopy. Patients and Methods: This work had two phases: an in vitro study, using an interference detector, and an in vivo study involving 20 patients with cardiac pacemakers who showed symptoms or signs that justified a capsule endoscopy investigation. Results: No interference was observed during the first, in vitro, phase of the study. In the second phase, patients wore a Holter recorder for a mean time of 10 hours, during which the average number of recorded QRS complexes exceeded 30000. All the pacemakers functioned normally. Interference due only to myopotentials was detected in a single patient in whom modification of the pacemaker programming was necessary. In the other 19 patients, neither sensing nor stimulation failures were observed. Conclusions: No interference between the pacemaker and the endoscopic capsule was observed. All the pacemakers functioned normally, and no increased incidence of adverse effects was observed. Neither was any pacemaker-induced interference observed on the capsule endoscopy images.