Electrophysiologic endocardial mapping from a noncontact nonexpandable catheter: A validation study of a geometry-based concept

Introduction: The need for high-resolution simultaneous mapping of cardiac excitation and arrhythmias on a beat-by-beat basis is widely recognized. Here we validate a noncontact mapping approach that combines a spiral catheter design with mathematical reconstruction to generate potential maps, electrograms, and activation maps (isochrones) on the entire left ventricular endocardial surface during a single beat. The approach is applicable to any heart chamber. Methods and Results: The catheter is 3 mm (9 French) in diameter and carries 96 electrodes. Reconstruction accuracy is evaluated through direct comparison with endocardial data measured with 95 needle electrodes. Results show that endocardial potentials, electrograms, and isochrones are reconstructed with good accuracy during pacing from single or multiple sites (simulating ectopic activity). Pacing sites can be located to within 5 mm of their actual position, and intersite distances of 17 mm can be resolved during dual pacing. The reconstructed potential pattern reflects the intramural depth of pacing. The reconstructions are robust in the presence of geometric errors, and the accuracy is minimally reduced when only 62 catheter electrodes are used (32 are sufficient for pacing site localization). Conclusion: The study demonstrates that simultaneous endocardial mapping can be accomplished during a single beat from a spiral-shaped noncontact catheter with good accuracy.