Clinicians are confronted every day with a growing number pacemakers (PMs), implantable cardioverter-defibrillators (ICDs) and implantable loop recorders (ILRs). Collectively these devices are sub summarized as cardiac rhythm management devices (CRMDs). Identification of these devices is simple as long a the patient can present an ID card or some other form of identification. This can become challenging especially in emergencies where such information might not be accessible and interrogation of the pacemaker becomes a problem.
Using the wrong manufacturer-specific device programmer causes delay in diagnostic and treatment and can be relevant in these situations.
Techniques to identify a CRMD are following:
- Patient's ID card
- Medical records
- Manufacturers' patient registries (All CRMD manufacturers keep their own in-house registry of patients implanted with their devices and provide 24-hour telephone technical support
- Device specific radiopaque alphanumeric codes (ANC)
All these identification techniques have their problems in clinical practice and so far no other technique or algorithm was available to help out in such a dilemma. Sony Jacob et al. have therefor developed and validated the so called
Cardiac Rhythm Device Identification Algorithm using X-rays (CaRDIA-X, see below)
The study participants using this algorithm showed an overall accuracy of 96.9%. This study was published in 2011 but only now caught our attention.
We have tried this algorithm on a few X-rays ourselves and came to the conclusion:
Using the chart is a little challenge itself, but very helpful in most cases! Certainly worth keeping in mind!
Jacob S et al. Heart Rhythm. 2011 Jun;8(6):915-22.