Noncontact charge-density mapping accurately reconstructed endocardial activation with a median spatial error of 1.73 mm compared to 2.41 mm for voltage mapping, providing a 4-fold improvement in spatial resolution.
Observational (n=25)
Yes
Does noncontact charge-density mapping improve the spatial and temporal resolution of endocardial activation maps compared to voltage-based mapping in patients with atrial arrhythmias?
Charge-density mapping provides significantly higher spatial and temporal resolution than conventional voltage mapping, enabling the identification of localized therapeutic targets in atrial fibrillation.
Absolute Event Rate: 1.73% vs 2.41%
BACKGROUND: Spatial resolution in cardiac activation maps based on voltage measurement is limited by far-field interference. Precise characterization of electrical sources would resolve this limitation; however, practical charge-based cardiac mapping has not been achieved. METHODS: A prototype algorithm, developed from first principles of electrostatic field theory, derives charge density (CD) as a spatial representation of the true sources of the cardiac field. The algorithm processes multiple, simultaneous, noncontact voltage measurements within the cardiac chamber to inversely derive the global distribution of CD sources across the endocardial surface. RESULTS: Comparison of CD to an established computer-simulated model of atrial conduction demonstrated feasibility in terms of spatial, temporal, and morphologic metrics. Inverse reconstruction matched simulation with median spatial errors of 1.73 mm and 2.41 mm for CD and voltage, respectively. Median temporal error was less than 0.96 ms and morphologic correlation was greater than 0.90 for both CD and voltage. Activation patterns observed in human atrial flutter reproduced those established through contact maps, with a 4-fold improvement in resolution noted for CD over voltage. Global activation maps (charge density-based) are reported in atrial fibrillation with confirmed reduction of far-field interference. Arrhythmia cycle-length slowing and termination achieved through ablation of critical points demonstrated in the maps indicates both mechanistic and pathophysiological relevance. CONCLUSION: Global maps of cardiac activation based on CD enable classification of conduction patterns and localized nonpulmonary vein therapeutic targets in atrial fibrillation. The measurement capabilities of the approach have roles spanning deep phenotyping to therapeutic application. TRIAL REGISTRATION: ClinicalTrials.gov NCT01875614. FUNDING: The National Institute for Health Research (NIHR) Translational Research Program at Royal Papworth Hospital and Acutus Medical.
Grace et al. (Thu,) conducted a observational in Atrial fibrillation and atrial flutter (n=25). Noncontact charge-density (CD) mapping (AcQMap) vs. Voltage-based mapping was evaluated on Median spatial error (Distance to Origin) in localizing focal activation. Noncontact charge-density mapping accurately reconstructed endocardial activation with a median spatial error of 1.73 mm compared to 2.41 mm for voltage mapping, providing a 4-fold improvement in spatial resolution.