Catheter insertion in the EP study is conducted through two large blood vessels. One catheter is inserted into the neck while another one in the groin. The catheter entering blood vessels through the neck enters the top of the heart and the catheter entering blood vessels in the groin enters the bottom of the heart. Thus, by entering catheters through distinct directions doctors are able to assess and diagnose the source of abnormal rhythm in a better way.
Nevertheless, removal of catheters from neck and groin areas will leave back a tiny hole which will appear like a bug bite. There is no requirement of stitches and it will leave no scars.