As you indicate -2-27 (ECG monitoring equipment) demands defibrillation protection.
And, with the proliferation of automatic AED it may not be possible to justify not having protection if just used in a clinic.
But look closely at the 'Scope' of -2-27. It describes the expected use and environment of use and specifically excludes some devices (eg ECG telemetry). So, it might be a better idea to exclude all of -2-27. Perhaps a better choice of 'Particular' standard would be -2-51 (recording and analysing ECG).
I don't have a copy so do not know of it's handling of defibrillation protection.