I am currently working with an ECG cable, is there a way for me to test the integrity of the shielding of the cable without using it directly on an ECG monitor to check for interference.
Cable shielding depends on the % coverage by the woven braid with its gaps. Thus a solid shield (aluminum? foil) with a contact wire is the better type of coax cable.
For excellent control of electric fields, the external fields must NOT be able to find a path to the center-conductor. Hence the need for a solid(foil)shield, not a woven shield.
All this will get you some Electric Field shielding.
Magnetic fields are a different matter.