Standardized unfold mapping: a technique to permit left atrial regional data display and analysis

• Published in: Journal of interventional cardiac electrophysiology Vol. 50; no. 1; pp. 125 - 131
• Main Authors: Williams, Steven E., Tobon-Gomez, Catalina, Zuluaga, Maria A., Chubb, Henry, Butakoff, Constantine, Karim, Rashed, Ahmed, Elena, Camara, Oscar, Rhode, Kawal S.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.10.2017; Springer Nature B.V
• Subjects: Ablation; Aged; Arrhythmia; Atrial Fibrillation - diagnostic imaging; Atrial Fibrillation - surgery; Body Surface Potential Mapping - methods; Body Surface Potential Mapping - standards; Cardiology; Catheter Ablation - adverse effects; Catheter Ablation - methods; Cohort Studies; Data Display; Data processing; Eye; Female; Heart; Heart diseases; Humans; Imaging; Integrals; Magnetic resonance; Magnetic Resonance Imaging, Cine - methods; Male; Mapping; Medicine; Medicine & Public Health; Middle Aged; Multimedia Report; Observer Variation; Parameterization; Prospective Studies; Regional analysis; Reproducibility; Reproducibility of Results; Sensitivity and Specificity; Severity of Illness Index; Standardization; Sums; Ventricle; Contact-force analysis; Unfold map; Atrial fibrillation; Catheter ablation; Regional analysis; Cardiac magnetic resonance
• ISSN: 1383-875X; 1572-8595; 1572-8595
• DOI: 10.1007/s10840-017-0281-3

Purpose Left atrial arrhythmia substrate assessment can involve multiple imaging and electrical modalities, but visual analysis of data on 3D surfaces is time-consuming and suffers from limited reproducibility. Unfold maps (e.g., the left ventricular bull’s eye plot) allow 2D visualization, facilitate multimodal data representation, and provide a common reference space for inter-subject comparison. The aim of this work is to develop a method for automatic representation of multimodal information on a left atrial standardized unfold map (LA-SUM). Methods The LA-SUM technique was developed and validated using 18 electroanatomic mapping (EAM) LA geometries before being applied to ten cardiac magnetic resonance/EAM paired geometries. The LA-SUM was defined as an unfold template of an average LA mesh, and registration of clinical data to this mesh facilitated creation of new LA-SUMs by surface parameterization. Results The LA-SUM represents 24 LA regions on a flattened surface. Intra-observer variability of LA-SUMs for both EAM and CMR datasets was minimal; root-mean square difference of 0.008 ± 0.010 and 0.007 ± 0.005 ms (local activation time maps), 0.068 ± 0.063 gs (force-time integral maps), and 0.031 ± 0.026 (CMR LGE signal intensity maps). Following validation, LA-SUMs were used for automatic quantification of post-ablation scar formation using CMR imaging, demonstrating a weak but significant relationship between ablation force-time integral and scar coverage ( R 2  = 0.18, P  < 0.0001). Conclusions The proposed LA-SUM displays an integrated unfold map for multimodal information. The method is applicable to any LA surface, including those derived from imaging and EAM systems. The LA-SUM would facilitate standardization of future research studies involving segmental analysis of the LA.