3D Map of Heart Electrical Wiring Aims to Guide Congenital Heart Repair

Tetralogy of Fallot is one of the most common congenital heart problems and often requires surgery in infancy. Many survivors later develop conduction abnormalities because the cardiac electrical system is damaged or displaced and remains invisible during operations. Surgeons rely on anatomical landmarks that can be imprecise in this setting. Researchers have now created a three-dimensional map of the heart’s conduction system in tetralogy of Fallot to guide safer repair.

Using Hierarchical Phase-Contrast Tomography (HiP-CT), investigators at University College London (UCL) and the European Synchrotron Radiation Facility (ESRF) produced the first 3D map of conduction tissues in this disease. The work is part of the Human Organ Atlas collaboration, which seeks to visualize whole organs with unprecedented detail. Findings are published in the Journal of Thoracic and Cardiovascular Surgery on June 1, 2026.

HiP-CT is powered by the European Synchrotron’s Extremely Brilliant Source, delivering an X-ray beam intensity up to one million times higher than conventional hospital computed tomography. The approach scans whole human organs ex vivo and then zooms to near-cellular resolution down to 2 microns. This experimental study used human tissue samples to capture intact anatomy non-destructively.

Researchers examined 18 whole human heart specimens with and without tetralogy of Fallot and reconstructed the specialized fibers that carry electrical impulses. In the disease, the right ventricular conduction tissue did not follow the usual course seen in healthy hearts. Instead, it appeared thinner and spread across the ventricular septum in a draped pattern, prompting a revision of surgical landmarks.

The analysis identifies where conduction pathways run within the myocardium, information that could help surgeons avoid iatrogenic injury and potentially reduce postoperative electrical disorders. The team also developed computational tools to handle large datasets and present the anatomy in immersive three-dimensional environments. Models can be transferred into virtual reality and 3D-printed for surgical training.

The Human Organ Atlas now offers an open-access 3D portal that brings together highly detailed organ images. The consortium involves scientists and clinicians from nine institutes and continues to expand. Related efforts within the European Research Collaborative of Cardiac Archives (EuReCCA) are extending this work to other congenital defects, including single ventricle disease.

“These data are the result of several years of development of the HiP-CT technique. It was initially developed at the ESRF during the COVID-19 pandemic to study human lungs. In few years, the data quality and acquisition speed dramatically increased, making possible to scan enough organs to perform relevant studies on important pathologies,” said Paul Tafforeau, ESRF scientist and pioneer of this imaging technique used to create the Human Organ Atlas.

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