Noncontact multielectrode array mapping accurately reconstructed endocardial unipolar electrograms, with cross-correlation of 0.87 (95% CI 0.84-0.91) at distances <34 mm.
Observational (n=13)
Does a noncontact multielectrode array accurately reconstruct endocardial unipolar electrograms compared to contact mapping in the human left ventricle?
A noncontact multielectrode array can accurately reconstruct endocardial unipolar electrograms in the human left ventricle, provided the distance to the endocardium is less than 34 mm.
p-value: p=<0.001
BACKGROUND: Catheter ablation of ventricular tachycardia is limited in part by difficulty in identifying suitable sites for ablation. A noncontact multielectrode array (MEA) has been developed that allows reconstruction of 3360 electrograms, using inverse-solution mathematics, that are superimposed onto a computer-simulated model of the endocardium. This study assesses the accuracy of timing and morphology of reconstructed unipolar electrograms compared with contact unipolar electrograms from the same endocardial site. METHODS AND RESULTS: The MEA was deployed in the left ventricles of 13 patients (end-diastolic diameters, 61.7+/-8.4 mm mean+/-SD). We recorded contact electrograms at 76 points equatorial and 32 points nonequatorial to the MEA during sinus rhythm using a catheter-locator signal to record direction and distance from the MEA. Morphology (cross-correlation) and timing of maximum -dV/dt of contact and reconstructed electrograms were compared at different distances from the MEA center to endocardium (M-E) and from the MEA equatorial plane. For equatorial data, the M-E was 32.12+/-12.12 mm. The timing of reconstructed with respect to contact electrograms was -1.94+/-7.12 ms for M-E 34 mm (P34 mm, respectively. Nonequatorial points were 32.33+/-10.81 mm (range, 16.9 to 55.6 mm) from the MEA equatorial plane; electrogram timing difference was -8.97+/-15.75 ms and was unrelated to this distance from the equator. CONCLUSIONS: This noncontact mapping system accurately reconstructs endocardial unipolar electrograms from the human left ventricle. At M-E distances >34 mm, timing accuracy of reconstruction decreases.
Schilling et al. (1998) conducted an observational in Ventricular tachycardia (n=13). Noncontact multielectrode array (MEA) vs. Contact unipolar electrograms was evaluated on Accuracy of timing and morphology (cross-correlation) of reconstructed unipolar electrograms (p=<0.001). Noncontact multielectrode array mapping accurately reconstructed endocardial unipolar electrograms, with cross-correlation of 0.87 (95% CI 0.84-0.91) at distances <34 mm.