Health UK (Commonwealth Union) – A recent study led by the University College London (UCL) researchers suggests that a reusable vest capable of finely mapping the electrical activity of the heart could enhance the identification of individuals at a high risk of sudden cardiac death.
The human heart’s contraction is triggered by electrical signals that regulate the heartbeat. Heart rhythm disorders affecting two million people in the UK can lead to sudden death when these signals malfunction.
Historically, detailed mapping of the heart’s electrical activity was uncommon, necessitating either the insertion of a catheter into the heart or the use of single-use devices, which were both expensive and time-consuming to set up, often involving radiation exposure.
However, the UCL research team has developed an electrocardiographic imaging (ECGI) vest, outlined in a recent paper in the Journal of Cardiovascular Magnetic Resonance, which has the potential for widespread use in standard care. The vest is reusable, time-efficient, and requires only five minutes per patient.
Equipped with 256 sensors, the vest captures electrical data that, when combined with detailed MRI images of the heart’s structures, enables the generation of 3D digital models illustrating the heart and the patterns of electrical activity coursing through it.
Dr Gaby Captur of the UCL Institute of Cardiovascular Science and the Royal Free Hospital, London, who formed the vest after receiving funds from the British Heart Foundation (BHF) and the Society for Cardiovascular Magnetic Resonance, says “We identified a problem in cardiology. Heart imaging has made remarkable progress in recent decades, but the electrics of the heart have eluded us. The standard technology to monitor the heart’s electrical activity, the 12-lead electrocardiogram (ECG), has barely changed in 50 years.
“We believe the vest we have developed could be a quick and cost-effective screening tool and that the rich electrical information it provides could help us better identify people’s risk of life-threatening heart rhythms in the future.
“In addition, it can be used to assess the impact of drugs, new cardiac devices, and lifestyle interventions on heart health.
“Currently, predicting risk of sudden cardiac death is difficult, as it is not known, for instance, how risk might be affected by a particular structural feature or abnormality of the heart.”
Dr. Matthew Webber, a collaborator in the development of the vest from the UCL Institute of Cardiovascular Science, emphasized the significance of Cardiac MRI as the gold standard for heart imaging. This method provides insights into the health of the heart muscle, including the identification of areas with deceased muscle cells. Dr. Webber highlighted the complementary role of in-depth electrocardiographic imaging, which aids in correlating these features with their consequences on the heart’s electrical system, addressing a crucial aspect of the puzzle.
The researchers argue that improved risk stratification would assist clinicians in identifying individuals who would benefit from an implantable cardioverter defibrillator (ICD). ICDs monitor heart rhythm and administer shocks to restore a normal rhythm when necessary, potentially saving lives. However, they also carry risks such as infection and the potential for distress if unnecessary shocks are delivered.
To enhance predictive capabilities, potential biomarkers identified through Electrocardiographic Imaging (ECGI) need validation through longitudinal studies. These studies would track individuals over time to ascertain whether these biomarkers are indeed associated with elevated risk outcomes or not.
A notable feature of the ECGI vest is its reusability, made possible by the use of dry electrodes. These electrodes can be washed between uses, eliminating the need for gel typically required with metallic electrodes. This marks the first instance of such electrodes being employed in ECGI.
The feasibility of the vest was assessed in a study involving 77 patients, and the results, published in the Journal of Cardiovascular Magnetic Resonance, confirmed its reliability and durability. Subsequent successful use in 800 patients underscores its practical application. Notably, prior to 2020, studies mapping heart electrical activity typically included only 20 or 30 patients at most.
