Atrial tachycardia (AT) is a common cardiac arrhythmia associated with serious health risks, including stroke, heart failure, and long-term atrial dysfunction. Although catheter ablation is an established treatment, complex ATs remain particularly difficult to manage. Current mapping systems rely heavily on manual interpretation by electrophysiologists (EPs), which can lead to variability in diagnosis, suboptimal ablation strategies, and arrhythmia recurrence. In addition, the field lacks a universally accepted classification system for AT subtypes, contributing to diagnostic uncertainty and inconsistent treatment approaches.
The AT-TOP project addresses these limitations through a fundamentally new, topology-based framework for understanding and treating AT. Building on discoveries from the ERC-funded SMARTHEART project, AT-TOP introduces a mathematically grounded classification system based on the concept of complete and incomplete reentry loops. Our research has demonstrated that each AT contains two interconnected loops: a dominant complete loop that sustains the ongoing arrhythmia, and a suppressed incomplete loop that remains latent but can become active if the primary loop is ablated. This dual-loop structure, rooted in topological principles, has been consistently confirmed in computational simulations and across a large set of clinical cases. We define the anatomical boundaries around which the dominant complete loop and the suppressed incomplete loop rotate as critical boundaries.
To translate this insight into clinical practice, we have developed Directed Graph Mapping (DGM), a software tool that automatically detects the critical boundaries, classifies AT types using patient-specific anatomical topology, and predicts how the arrhythmia may evolve after ablation. Importantly, DGM shifts mapping from a purely diagnostic approach to a predictive one: it not only helps terminate the current arrhythmia but also anticipates and prevents recurrence by identifying loops that would otherwise remain undetected.
The primary objectives of the project are:
* To validate the clinical value of DGM in a large-scale prospective study targeting participation from 5 hospitals. Data collection has been successfully initiated across multiple centres, and a substantial multicentre dataset comprising approximately 500 clinical AT cases is currently being analysed.
* To further optimize the DGM algorithms for robust, automated detection and classification of AT based on patient-specific anatomical maps.
* To establish a future roadmap for DGM in terms of valorization
The expected impact of AT-TOP is multifaceted:
* Clinical impact:** Shorter and more accurate ablation procedures, reduced recurrence rates, and improved long-term patient outcomes.
* Operational impact:** Fewer repeat procedures and more efficient use of hospital resources.
* Scientific impact:** Introduction of a mathematically rigorous and clinically validated classification framework that may establish a new standard in arrhythmia management.
* Economic and societal impact:** Broader access to advanced diagnostics, healthcare cost reductions, and improved quality of life for patients.
Beyond engineering and clinical electrophysiology, the project highlights the power of interdisciplinary collaboration. By integrating mathematical topology and network theory into cardiology, AT-TOP provides a common conceptual language for electrophysiologists, supports standardization, and strengthens collaboration across centres.
In summary, AT-TOP translates fundamental scientific insight into a clinically actionable and predictive tool. By redefining how atrial tachycardia is classified and treated, the project has the potential to establish a new paradigm in arrhythmia management and open the door to similar advances in other complex cardiac disorders.
