A wireless LAN using the 2.4GHz band has a power output of less than 10mW per 1MHz bandwidth. In the survey conducted by the Ministry of Internal Affairs and Communications and the Ministry of Health, Labor, and Welfare mentioned above, the output power of wireless LAN when transmitting data continuously was 20mW, which is 1/4 of that of PHS cell phones, indicating that wireless LAN has little impact on medical devices. On the other hand, 5 to 25% of PHS cell phones affect medical equipment such as monitoring equipment and blood circulation equipment.
The strength of radio wave radiation depends not only on the transmit power, but also on the distance. Although the intensity of radiation from a wireless router is much less than that from an FM radio station, a wireless router is also much closer to a pacemaker, and ultimately, according to the inverse square ratio, the radiation received from the wireless router is actually still much larger. And pacemakers receive much more power from cell phones, Bluetooth headsets, and other wireless devices that are much closer to the body than from wireless routers.
Pacemakers are built not to work, and only begin to work after they are implanted in the human body, so there is no effect before implantation, and there is no effect after implantation. In fact, the effects of this electromagnetic radiation are multifaceted, there may be a one-time damage, or there may be two occasional failures to work, and in fact the latter is much more likely to happen (two occasional failures may be fatal).
In short, err on the side of caution and wear your pacemaker as far away from radio equipment as possible.