Simultaneous Comparison of Electrocardiographic Imaging and Epicardial Contact Mapping in Structural Heart Disease

Abstract

Background: The accuracy of ECG imaging (ECGI) in structural heart disease remains uncertain. This study aimed to provide a detailed comparison of ECGI and contact-mapping system (CARTO) electrograms. Methods: Simultaneous epicardial mapping using CARTO (Biosense-Webster, CA) and ECGI (CardioInsight) in 8 patients was performed to compare electrogram morphology, activation time (AT), and repolarization time (RT). Agreement between AT and RT from CARTO and ECGI was assessed using Pearson correlation coefficient, ρ AT and ρ RT , root mean square error, E AT and E RT , and Bland-Altman plots. Results: After geometric coregistration, 711 (439–905; median, first-third quartiles) ECGI and CARTO points were paired per patient. AT maps showed ρ AT =0.66 (0.53–0.73) and E AT =24 (21–32) ms, RT maps showed ρ RT =0.55 (0.41–0.71) and E RT =51 (38–70) ms. The median correlation coefficient measuring the morphological similarity between the unipolar electrograms was equal to 0.71 (0.65–0.74) for the entire signal, 0.67 (0.59–0.76) for QRS complexes, and 0.57 (0.35–0.76) for T waves. Local activation map correlation, ρ AT , was lower when default filters were used (0.60 (0.30–0.71), P =0.053). Small misalignment of the ECGI and CARTO geometries (below ±4 mm and ±4°) could introduce variations in the median ρ AT up to ±25%. Minimum distance between epicardial pacing sites and the region of earliest activation in ECGI was 13.2 (0.0–28.3) mm from 25 pacing sites with stimulation to QRS interval <40 ms. Conclusions: This simultaneous assessment demonstrates that ECGI maps activation and repolarization parameters with moderate accuracy. ECGI and contact electrogram correlation is sensitive to electrode apposition and geometric alignment. Further technological developments may improve spatial resolution.

In silico validation of electrocardiographic imaging to reconstruct the endocardial and epicardial repolarization pattern using the equivalent dipole layer source model

“…They describe that 78% of the 240 compared epicardial electrograms had a difference between reconstructed and measured activation recovery intervals of less than 10 ms with the epicardial potential method. A study by Graham et al directly compares reconstructed epicardial repolarization patterns with CARTO electroanatomical maps in patients with structural heart disease, and found correlation of repolarization sequences of 0.55 and RMSE of 51 ms [13]. Although it is difficult to directly compare these studies with the current study, our study shows results that are equivalent or even superior to the results from the other studies.…”

Impact of pulmonary vein isolation on mechanisms sustaining persistent atrial fibrillation: Predicting the acute response

“…AF is arguably the most difficult arrhythmia to map noninvasively. Validation work in the ventricle has shown a moderate correlation between ECGI predicted activation times and that on epicardial contact mapping 24‐26 . The accuracy may be further reduced in areas of low voltage and the system may have difficulty identifying lines of the block.…”

“…Validation work in the ventricle has shown a moderate correlation between ECGI predicted activation times and that on epicardial contact mapping. [24][25][26] The accuracy may be further reduced in areas of low voltage and the system may have difficulty identifying lines of the block. The atria are also anatomically complex and the atria cannot be separated at the septum.…”

Surface unipolar electrogram characteristics to predict site of origin of outflow tract arrhythmias using noninvasive mapping

“…The 12‐lead ECG has been the main diagnostic modality for that purpose, however given the anatomical complexity of outflow tract region, proposed ECG algorithms are often cumbersome and lack specificity 14–17 . Prior studies have shown that NIEAM can reliably identify chamber of origin for OTVAs and can prevent unnecessary access and mapping, therefore reducing overall procedure time 10–12,18,19 . These studies have relied on general patterns of activation and while they provide insight on the chamber that is activated first, they cannot predict the exact SOO.…”