What is EPS/RFA?
EPS stands for electrophysiology study. EPS is done by introducing small electrodes into the heart, usually through veins (blood vessels carrying deoxygenated blood) in the groin or the neck. Each electrode catheter has 4 to 20 electrodes or more. The end of the electrode catheter outside the body is connected to a switch box which in turn connects to a multi channel monitor which records electrograms from different parts of the heart. The record can be analysed to find the origin of abnormal heart rhythm and conduction. A signal generator is used to give electrical signals to various parts of the heart to assess conduction of the signals and to see if a fast automatic rhythm can be induced. In case it is induced, the ECG is compared with that which occurs during the spontaneous abnormal rhythm.
RFA stands for radiofrequency catheter ablation. After locating the source of the abnormal heart rhythm or conduction by EPS, an ablation catheter is used to deliver radiofrequency electrical energy to the spot to produce tiny superficial burns which will eliminate the abnormal focus or pathway of conduction. This process is known as RFA. Ablation catheters are thicker and have thicker wires taking higher currents to the tip, which has a higher surface area (typically 4 mm or 8 mm) to deliver higher energy than the diagnostic catheters.