Electrophysiology provides evaluation, diagnosis and therapy for conditions such as atrial fibrillation, heart arrhythmias, sudden cardiac arrest and congestive heart failure. During an electrophysiology (EP) study an electrode catheter is inserted into a blood vessel in the leg and/or neck and threaded to the heart. Once the catheter reaches the heart, electrodes gather data and a variety of electrical measurements are made. This test is used to determine if there are any abnormalities and, in some cases, can be used to treat or correct certain conditions.