Verification of linear lesions using a noncontact multielectrode array catheter versus conventional contact mapping techniques

Noncontact Verification of Linear Lesions. Introduction: Creation of linear lesions is an established ablation goal. Verification of complete conducti on block at the ablation line is required to determine ablation success. Co nventional mapping techniques are sequential endocardial activation mapping and documentation of double potentials. Recently, a noncontact multielectr ode array catheter was developed that allows instantaneous three-dimensiona l mapping by simultaneous reconstruction of > 3,000 electrograms. In this s tudy, we prospectively compared the accuracy of noncontact mapping to ident ify discontinuities in linear lesions and to verify a conduction block with that of conventional mapping techniques. Methods and Results: In 12 patients with atrial butter, radiofrequency puls es were applied between the tricuspid annulus and either the inferior vena cava or the eustachian ridge. Following each application, pulse propagation at the ablation line was determined during pacing by conventional mapping techniques. The findings were compared to high-density isopotential mapping using the noncontact multielectrode array catheter. It was found that nonc ontact mapping reliably distinguished conduction delays from a conduction b lock as defined by contact mapping. In addition, noncontact mapping instant aneously identified the area where a discontinuing in the line of block was present. In these patients, complete conduction block was achieved by radi ofrequency pulses guided by the noncontact mapping system. Conclusion: Noncontact mapping is highly accurate in distinguishing conduct ion delays from a complete conduction block. By providing an instantaneous high-density propagation vector at all sites along the ablation line, three -dimensional isopotential mapping is helpful in localizing discontinuities of linear lesions and, thus, mag facilitate the creation of a complete cond uction block.