Discussion
skin irritation, AF
EVENTS, RECURRENCE, PACS
A Garment ECG using hitoeLong-term ECG monitoring options for AF are being explored using implantable devices and non-invasive external recorders. However, implantable devices are expensive and not covered by health insurance, and non-invasive recorders often provide false positives or are otherwise unreliable [In the present study the ECG acquisition rate for the Garment ECG was 82.4%, with noise accounting for the difference between the actual acquisition rate and 100.0%. However, even at this noise level, results from our study support the clinical usefulness of this 2-week wearable system. Because the system is constructed in the form of a garment, there are some concerns that the electrode might shift with body movement, which could increase noise. Our pilot study showed a slightly higher ratio of noise signals than for the 24-hour Holter ECG, but the noise signals did not affect heart rate and were thus considered not to be clinically important [Garment ECG monitoring showed evidence of AF recurrence among 12 patients at non-uniform intervals during the 2 weeks of monitoring, including 1 patient whose first recurrence occurred at the very end of the monitoring period. This suggests that AF recurrence may be underdiagnosed by Holter ECG monitoring for two reasons: because post-ablation AF occurs only rarely in some patients, and also because the timing of those occurrences is highly non-uniform. In addition, 8 of 12 patients were asymptomatic in this study, supporting previous findings that post-ablation AF recurrence is frequently asymptomatic and can only be diagnosed from ECG recordings [The incidence of AF may vary depending on the patient population, and long-term monitoring will be especially beneficial in patients with lower AF incidence. The Garment ECG can support even more prolonged monitoring in the future by providing improved longer-term data storage and higher-capacity batteries while continuing to eliminate the risk of accidental patch removal. This system thus may prove more beneficial than wearable patch-type devices, not only in post-ablation patients but also in a wider population of patients who need access to this type of monitoring.Because PACs can trigger AF, we also assessed the incidence of PACs using Garment and Holter ECGs. The difference in results was statistically significant but had no clinical significance, showing the same median value of 0.09% for both devices.While patch-type ECG monitors with gel-type electrodes have been associated with mild skin irritation in some patients [One limitation of this study was the fact that, because the Garment ECG monitoring system with a dry electrode is not waterproof, AF monitoring time was interrupted when the patients removed the garment to bathe. Another limitation was the small sample size of this study, with only 12 out of 67 patients experiencing recurrent AF after ablation. Although we found a significant difference in the detection of post-ablation AF events between the 2 groups, further studies in a larger population are warranted. In assessing the risk of bias in this study [In conclusion, continuous 2-week recording with a garment-style wearable ECG monitor equipped with a textile electrode showed a higher extent of AF recurrence than with a Holter 24-hour ECG monitor. The 2-week monitoring period more than compensated for the lower acquisition rate of the Garment ECG system, revealing a higher level of hidden AF recurrence than was recorded with the Holter 24-hour ECG.