British scientists propose new imaging method for cardiac arrhythmias

Cardiac arrhythmias, or heart conditions caused by irregular, slow, or accelerated beating of the heart, have proven difficult to research and treat despite being among the biggest causes of morbidity in developed nations.

Reasons for this include a lack of existing insight on the fundamental triggers of fibrillation, effective clinical assessment and evaluation, and adequate surgery-guiding tools, according to Luca Marmugi, PhD, and Ferruccio Renzoni, PhD, of University College London, authors of a recently published article in the journal Nature: Scientific Reports.

“This is mainly due to the absence of tailored and effective diagnostic methods,” they wrote. “In fact, magnetocardiography and electrocardiography do not provide any direct information about the causes of the irregular beat and, more importantly, the structures producing it.”

The best way to directly image arrythmias, according to Marmugi and Renzoni, is through magnetic induction tomography (MIT), a recently developed technique for the investigation of the electrical and magnetic properties which provides a direct mapping of conductivity, permittivity and permeability without requiring physical contact with an object.

“[MIT] generates a non-invasive, space-resolved map of the heart’s conductivity, thus addressing directly the presence of permanent conduction anomalies and their relationship with the generation and the dynamics of atrial fibrillation and ventricular fibrillation,” they wrote. “In order to meet the requirements for such an instrument, we [designed] an MIT imaging system based on optical atomic magnetometers.”

Optical atomical magnetomenters (OAMs) are ideal in their hypothetical imaging tool, said Marmugi and Renzoni, as they solve the sensitivity and bandwidth issues of standard MIT systems to provide better detection of the MIT signal in an unshielded environment and at room temperature.

“The proposed application is technically feasible only thanks to the use of the optical atomic magnetometers’ array; however, the OAMs’ characteristics will also provide several advantages also in the daily clinical practice,” the authors wrote. “The direct mapping of the heart’s conductivity, indeed, allows to address simultaneously the anatomy, the physiology and the pathology of the heart, thus filling up the lack of dedicated diagnostic tools.”

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