Background: Conventional electroanatomical mapping systems require serial collection of data points, which can be time-consuming and render characterizing certain arrhythmias challenging. Non-contact ultrasound-based anatomical reconstruction and whole-chamber charge density (CD) mapping has been used to guide ablation in patients with persistent atrial fibrillation. Its value in ventricular chambers has not been explored.
Objective: To test the ability of the AcQMap High-Resolution Imaging and SuperMap System to rapidly and accurately reconstruct left ventricular (LV) anatomy and to delineate ischemic scar.
Methods: An anterior wall infarct was induced in a sheep. After 8 weeks, cardiac MRI was performed and 3D reconstructions of the LV created. An ultrasound and CD mapping catheter was advanced into the LV via transseptal access to generate SuperMap geometries. Scar was defined by late gadolinium enhancement and CD Laplacian amplitude thresholds on MRI and SuperMap, respectively. Corresponding points from both geometries were compared via pairwise analysis.
Results: Total SuperMap acquisition time was 2:27 minutes, resulting in 3,664 anatomical vertices. Scar areas were 17.62 and 18.06 cm² on MRI and SuperMap, respectively. ROC curves demonstrated AUC values of 0.92 and 0.93 for 25% transmural scar and total scar, respectively (accuracy 0.87 for both) (Figure).
Conclusion: Non-contact ultrasound-based LV anatomy and CD mapping was feasible, rapid, and demonstrated a high level of correlation with MRI parameters for identifying ischemic scar in this preclinical model. This technology could be valuable for the treatment of ventricular arrhythmias.