Limitations
There are several limitations to this study. First, this was a single-center study and the number of analyzed patients was relatively small. Second, atrial undersensing can occur during AHREs, which can lead to either a failure to detect an AHRE or the truncation of a single AHRE into multiple shorter episodes. Moreover, we could not analyze the duration of AHREs in detail as a device parameter in this study because its extraction from the device record was difficult. Third, there was a slight configuration difference apparent in the AHRE detection because of the different pacemaker manufacturers involved. Fourth, because the measurements of P-waves were based on morphological determinations of P-waves, some errors may have occurred. Finally, because we didn’t evaluate the correlation between PWD and the fu­ture detection of AF, further prospective studies are necessary that evaluate the relationship between PWD values and clinical AF in patients with AHRE.