CT Scans Show Not to Interfere with Heart Rhythm Devices

E-mail Print PDF


Back when US health administrators issued an advisory in 2008 warning that computed tomography (CT) imaging might interfere with pacemakers or implantable cardioverter-defibrillators, the medical community needed more evidence to support the health agency’s recommendations/suggestions.

According to a new study, researchers now have reported their findings of the first study to assess the apprehension in “real world,” medical practice. The results showed that such negative interference, if it exists, is not significant enough to warrant drastic changes in medical practice.

The study’s findings were published online February 2014, in the Journal of the American College of Cardiology. 

“The presence of cardiac devices should not delay or result in cancellation of clinically indicated CT imaging procedures,” stated the study’s senior author, Timm-Michael Dickfeld, MD, PhD, associate professor of medicine at the University of Maryland School of Medicine (Baltimore, MD, USA) and chief of electrophysiology at the Baltimore Veterans Affairs (VA) Medical Center.

The original US Food and Drug Administration (FDA) counseling, which prompted this study, recommended having a physician present during CT scans, ready to take emergency measures to manage possible adverse events, and to observe the rhythm device in the patient following CT imaging to provide correct function. An updated FDA advisory, issued in 2013, did not pay special focus to standard device checks but called for a physician to be available when the CT involves continuous scanning over the device for more than a few seconds.ct heart

“For CT scans for diagnostic purposes, the FDA advisory may warrant further evaluation,” said the study’s lead investigator, cardiovascular medicine fellow Ayman Hussein, MD.

In retrospect, the researchers studied the records of patients who received over 500 CT scans between July 2000 and May 2010 performed at the University of Maryland Medical Center and the Baltimore VA Medical Center. They searched for key adverse effects such as abnormally high or low heart rate, death, an immediate intervention, hospital admission, or secondary effects such as changes in the device caused by CT imaging. However, the scans did not produce any of the primary outcomes, while several slight secondary effects were noted in a small group of devices, but there was no clear tie to CT. Similar changes were seen in a group of devices not exposed to CT.

“Clinicians and the FDA are collectively committed to patient safety. We also must rely on outcome data that helps us decide on the course of action best for our patients. This study provides what is probably the best information we will have for years to come,” noted Dickfeld.

“At the very least, the study may provide valuable input for reevaluation of the FDA’s original advisory,” said study co-author and associate professor of diagnostic radiology and nuclear medicine at the University of Maryland School of Medicine, Jean Jeudy Jr., MD.

These signals are relayed buying clomid online safe which then is by a number of such as medial preoptic and paraventricular nulcei.