In the beginning of an electrophysiology study, it is important to gain venous and/or arterial access. This is essentially placing an intravenous catheter (an introducer sheath) into a vein and/or artery. For electrophysiology procedures, it is not uncommon to place three introducer sheaths into a single femoral vein.
First, the femoral artery and/or vein must be located so that the operator can access the circulation in order to perform an electrophysiology study. The operator can identify the appropriate location by palpating the groin area of the patient near the iliac crest and the ischial tuberosity, as well as the symphysis pubis.
The inguinal ligament extends from the iliac crest down to the symphysis pubis. About two-thirds of the way medial between this location, the operator should be able to palpate the femoral artery, below the femoral ligament. There is a triangle in which the femoral nerve, artery, and vein are located from lateral to medial. By using the mnemonic NAVel, you can remember that the nerve, the artery, and the vein are always facing the navel whether one proceeds from the right or left side. In other words, the nerve (N) is most lateral, followed by the artery (A), and then the vein (V) as the most medial of the structures.