A new method exists to detect and measure ablation gaps after treatment for atrial fibrillation

ulmonary vein isolation or ablation is a standard procedure in the treatment of atrial fibrillation, the most common arrhythmia caused by a problem in the electrical conductivity of the heart which is often triggered in the proximity of the pulmonary veins. This surgical procedure produces a lesion or scar that affects the veins, hampering the spread of the heart’s electrical signal.

Unfortunately, the lesion is often incomplete and becomes a combination of lesions and gaps in healthy tissue. These gaps can lead to treatment failure, since they are potential causes of the recurrence of atrial fibrillation. Cardiac magnetic resonance is a non-invasive method used to detect gaps, but it is a time-consuming process and, as it prone to high inter-observer variability, difficult to standardize.

It provides a standardized definition of the results of the intervention

A team of researchers, in a study published in the advanced online edition of the journal Medical Image Analysis, presents a new method for semi-automatically identifying and quantifying the ablation gaps through quantification using mathematical analytical methods of graph theory.

Marta Núñez García, Oscar Cámara and Konstantine Butakoff, researchers of the Physense research group of the Department of Information and Communication Technologies (DTIC) at UPF, in conjunction with researchers from King’s College London (United Kingdom), proposed a measure to estimate the percentage of gaps or voids around a vein that has undergone ablation. The method has been tested on synthetic and clinical data from 50 patients diagnosed with atrial fibrillation who underwent pulmonary vein isolation with radiofrequency ablation.

On the data processed with this new method the researchers were able to conclude that left superior pulmonary vein is more prone to lesion gaps while the left inferior pulmonary vein is less so, which could be very useful for the optimization and objective assessment of PVI interventions. Hence, this work provides decision-making tools from the study of the results of the segmentation of lesions obtained in a group of patients.

Reference work:

Marta Núñez-García, Òscar Cámara, Mark D. O’Neill, Reza Razavi, Henry Chubb, Konstantine Butakoff (2018), “Mind the gap: Quantification of incomplete ablation patterns after pulmonary vein isolation using minimum path search”, Medical Image Analysis, advanced online edition. https://doi.org/10.1016/j.media.2018.10.001.