What is the reason for and aim of the publication?
Three-dimensional imaging and high-resolution electroanatomical mapping modalities have become an integral part of cardiology and cardiac electrophysiology. However, to perform differentiated regional analyses or catheter ablation approaches targeting specific areas, a universal definition of atrial regions and their boundaries is required. Such a universal definition will foster automated regional stratification and facilitate the employment of digital health- and artificial intelligence-based approaches.
While a standardized regionalization of the left ventricle has been produced by the American Heart Association (AHA) in its 17-segment model, which is widely accepted and routinely applied, there is no such consensus for the atria.
Our Clinical Consensus Statement is a joint effort of the European Heart Rhythm Association (EHRA) and the European Association of Cardiovascular Imaging (EACVI) of the European Society of Cardiology (ESC) that aimed to define standard atrial regions in a consistent manner across imaging, electroanatomical mapping, and computational modeling techniques, defining their borders with sufficient precision to permit reproducible and automated regionalization.
What are the most important take-home messages?
- This consensus document provides a standardized regionalization of the cardiac atria for 3D imaging, electroanatomical mapping, and computational modeling.
- The regionalization in this 15-segment bi-atrial model is based on anatomical, functional and clinical considerations and was developed in a multidisciplinary writing group consisting of cardiologists, cardiac electrophysiologists, cardiovascular imaging specialists and anatomists.
- The model enables consistent regional analyses and homogeneous data acquisition across different centers and modalities. Reproducibility and universal applicability were validated by use of two software algorithms for automatic regionalization, which were independently developed by the writing group.
- Regarding the management of patients with atrial arrhythmias, these standard regions with a universal and precise definition of regional borders will also enable reproducible regional ablation approaches.
Central Illustration. 15-segment bi-atrial model. Illustrated visualization of the 15 left and right atrial segments in different views, and head-to-head comparison with anatomical sections, as well as electroanatomical mapping and clinical routine CT-imaging in the corresponding views. Left column: posterior-anterior view; middle column: left anterior oblique view; right column: right anterior oblique view. CS, coronary sinus; IVC, inferior vena cava; LAA, left atrial appendage; LIPV, left inferior pulmonary vein; LSPV, left superior pulmonary vein; MA, mitral annulus (left atrioventricular junction); RAA, right atrial appendage; RIPV, right inferior pulmonary vein; RSPV, right superior pulmonary vein; SVC, superior vena cava; TA, tricuspid annulus (right atrioventricular junction).
What are challenges in practical implementation – and possible solutions?
Even with universally applicable standard atrial regions, the reproducibility of regional analyses and ablation strategies may be limited by the human factor, introducing inaccuracy, variability, and bias. These limitations are not unique and also apply to the widely used American Heart Association 17-segment model of the left ventricle.
To address this issue, we placed strong emphasis on the precise definition of regional boundaries, allowing reproducible identification of the respective atrial regions even in the absence of clear anatomical landmarks. Investigator-independent reproducibility across different imaging modalities was demonstrated using automated regionalization algorithms. The corresponding tools we developed for this purpose are available as dedicated regionalization software, with one implementation provided as open source.
Which issues still need to be tackled, that are not yet addressed by the paper?
A key remaining challenge is the dissemination and widespread implementation of the proposed standard. We are grateful that the European Society of Cardiology (ESC) as well as national cardiac societies, such as the German Cardiac Society (DGK), support this consensus and actively help to promote it. However, only widespread, uniform, and sustained adoption across the clinical, scientific, and educational communities will allow the full potential of standardized atrial regionalization to be realized.
Beyond endorsement by professional societies, integration into routine workflows, imaging software, electroanatomical mapping systems, and clinical training programs will be essential. Continued collaboration with industry partners, method developers, and guideline committees will therefore be required to translate the consensus from a conceptual framework into a broadly used clinical and research standard.
What further developments on the topic are emerging?
With ongoing technological advances and the rapid evolution of artificial intelligence, the relevance and complexity of three-dimensional imaging modalities and regional analyses continue to increase. In this context, the universal definitions provided by the present consensus anticipate the growing role of digital health– and AI-based approaches and create a robust framework for their development, validation, and clinical adoption. AI-enabled risk prediction based on regional atrial features, as well as personalized atrial fibrillation therapies using targeted, region-specific ablation strategies, are already emerging. Standardized atrial regions are a prerequisite to make such approaches reproducible, transferable across centers, and suitable for large-scale data-driven analyses.
Recognizing the current limitations in spatial resolution of clinically available imaging and mapping modalities, the proposed model was deliberately designed to balance universal applicability with anatomical accuracy. However, continued improvements in spatial resolution of imaging and electroanatomical mapping technologies are expected. These advances may enable a more refined anatomical representation, incorporating subtle landmarks and morphological features that are not yet accessible in routine clinical practice. Consequently, atrial regionalization concepts will likely evolve in parallel with technological innovation, allowing future adaptations that build upon and extend the current consensus framework.
Clinical consensus statement: Regionalization of the atria for 3D electroanatomical mapping, cardiac imaging, and computational modelling
Till F Althoff, Robert H Anderson, Christian Goetz, et al. Regionalization of the atria for 3D electroanatomical mapping, cardiac imaging, and computational modelling: a clinical consensus statement of the European Heart Rhythm Association and the European Association of Cardiovascular Imaging of the ESC, EP Europace, Volume 27, Issue 7, July 2025, euaf134, https://doi.org/10.1093/europace/euaf134
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