Electrophysiology hardware

Basic mapping catheters

Catheters used for electrophysiology studies (EPSs) and ablation are composed of multiple insulated wires encased in woven Dacron or polyurethane. Electrodes used in electrophysiology (EP) catheters are usually made of polished platinum-iridium alloy. Platinum is an inert and biologically safe metal with excellent electrical properties but is mechanically soft. The addition of iridium improves mechanical strength without affecting electrical performance. Electrode catheters are typically available in 3 to 8 French (F) diameters and 110 to 120 cm long. Usually 6F quadripolar, hexapolar, or decapolar deflectable catheters composed of 2 mm long electrodes (with a distal tip of 1 or 2 mm) separated by 5-mm distances are used for conventional EPS in adults ( Fig. 5.1 ). Deflectable catheters can be deflected in one or two directions (bidirectional) in the same plane. Smaller electrodes and narrow interelectrode distances (≤1 mm) may be needed for studying complex arrhythmias or multicomponent electrograms.