Post by @FTeranmd

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Image from Jacob et al. Heart Rhythm. 2011 Jun;8(6):915-22

We’ve all had a patient who shows up at the ED with a pacemaker or implantable cardioverter-defibrillator (ICD) that may be malfunctioning.  The patient didn’t bring the manufacturer ID card and isn’t sure about the make or model. So there you are, looking at the CXR, trying to identify the type — or at least the manufacturer. Is there anything we can actually look for to reliably identify these devices?

Introducing the CaRDIA -X radiologic identification system.

The number pacemakers (PMs),  implantable cardioverter-defibrillators (ICD), and implantable loop recorders (ILRs), collectively referred as cardiac rhythm management devices (CRMDs), is increasing exponentially each year. These patients often present to the Emergency Department with complaints that make interrogation of their devices necessary as part of their diagnostic management. Since patients tend to present to the ED unexpectedly, they often don’t have their device cards available, leaving the physician with limited clues to try to identify their CRDM type.

In a study by Jacob et al (2011) 50 physicians from different medical specialties were surveyed to assess the frequency of patients with CRMD encountered in their practice.  This study showed that approximately 80% of the providers had difficulties recognizing the type of CRMD. In response to this problem, the authors developed an algorithmic approach that based of a chest X-ray, allows to reliably identify the type of device. They called this algorithm the Cardiac Rhythm Device Identification Algorithm using X-rays (CaRDIA-X).

The algorithm consists of a six-step approach that includes searching for device-specific radiopaque alphanumeric codes (ANC), counting the number of leads and analyzing of the shape of the battery and can (device body).

The full text article can be found online at

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July 2024