Safety of Capsule Endoscopy With Implantable Cardiac Devices
David A. Johnson, MD. January 02, 2014

The evaluation of the pacemaker/ICD and capsule endoscopy interface showed that there was no interference between these devices. Similarly, when the ICD was used with the LVAD (as in the patients in whom we are finding increased need for using capsule endoscopy), there was no interference with the endoscopy capsule. The LVAD did not show any fluctuations in power, speed, flow, or pulsatility.

The third experiment showed no interference between the ICD and the endoscopy capsule, sequentially and cumulatively, with cell phones, pager, and laptop computer, all with radiofrequency transmissions. There was no interference on images from the capsule, and no interference with radiofrequency transmissions of the other devices.

In the last experiment, a 30-joule defibrillation shock was delivered with the ICD to determine whether it would interfere with the quality of the capsule image. Even at very close proximity to the ICD — a distance of only 1 cm — there was no interference with image acquisition by the capsule.

At institutions around the country, people say that the capsule endoscopy is contraindicated in patients who have these cardiac devices. In some circumstances, I have been told that a cardiologist must be in the room while the patient swallows the endoscopy capsule, which is a waste of time.

We can now say that there is no evidence — certainly from the relatively good cumulative data that we have from clinical retrospective and even prospective evaluations in humans, and now an excellent in vitro study that shows continued image clarity and a lack of interference when the two devices are used in very close proximity. I am even less concerned about this for 3 reasons:

• The Federal Communications Commission regulates the bandwidths on which wireless radiofrequency devices operate, and each device operates on a significantly different frequency. Overlap of the bandwidths of any of these technologies is uniformly absent.

• The radiofrequencies of these devices have very low power output, which is insufficient to influence other devices.

• The more recent wireless devices have improved input filters that filter out nondesignated radiofrequencies in the area.

We need to put a little bit of science behind the mayhem. The observational data combined with the in vitro data show that we can use these devices safely.
Capsule endoscopy can be used in complex cardiac patients without any concern. Although still contraindicated by the FDA and the product instructions, this needs to be evaluated on an individual basis. Show this study to your hospital administrators and cardiologists if they are reticent to do this. I’m Dr. David Johnson.