Background The application of a magnet over an implantable cardioverter defibrillator (ICD) will suspend tachycardia therapies. They are therefore useful in the rare circumstances when patients receive recurrent or inappropriate shocks. In our institution, magnets have been routinely issued to the majority of patients undergoing ICD implantation during the last 5 years, accompanied by an information leaflet explaining when and how to use the magnet. The purpose of this survey was to investigate how well this information had been retained, and in what circumstances the clinical magnets had been used.

Methods We sent a standardised to 476 patients, and received a response from 343 (72%). Data was collated using Microsoft Excel, and analysed using basic statistical methods.

Results 256 (74.6%) patients recalled being issued with a magnet. Collectively, these patients had received 503 years of ICD therapy (2.3+/-1.4 yrs per patient). 8% of patients, with an average exposure of 3.1+/- 1.2 years had used their magnets. Without prompts in the survey, patients were asked to recall the reason for use – these reasons are listed in Table 1. No cases of harm related to magnet use have come to our attention over this period.

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Abstract 23 Table 1

48% of patients issued with a magnet were still in possession of the written information at the time of survey. 62% of patients felt that they were able to remember when and how to use the magnet, and the retention of this information was dependent on how it had been delivered; with patients who had been given both written and verbal information demonstrating the greatest retention (Figure 1).

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Abstract 23 Figure 1

Conclusions In the early years of our service, patients with inappropriate ICD therapies experienced difficulties accessing magnets to suppress device therapies. We elected to issue magnets to our patients with instructions on their use. We evaluated reported magnet use and retention of information with this survey. The results suggest that a small but significant number of patients were able to utilise their magnets in clinically important situations. No adverse effects from magnet use were reported or have become know to us. Our survey suggests that the retention of this information amongst ICD patients is reasonable, but could be improved by ensuring all patients are given both verbal and written information when they receive their magnet, and that they are periodically reminded of this information when they attend follow-up.