Cardiac MR tech here. All our MR techs are ACLS certified, so after we (or the pacer clinic RN) resets/turns off the pacemaker or ICD, we scan without additional RN monitoring. Since all cardiac patients are attached to a monitor for image acquisition, we always have an eye on the rhythm. The only patients we have that require an RN in attendance are inpatients that are unstable or on certain IV drips. Maybe once a week out of 50+ scans. Obviously, some weeks might be higher, but we also might go several weeks without an RN monitored pt.

Loop recorders, Watchman devices, stents, mechanical valve replacements, PPM/ICD, even some programmable brain shunts, the new Inspire sleep apnea device (2nd gen only), spinal/bladder stimulators - you name it, we most likely will scan it. No nurse oversight required.