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Scientists at Durham University have developed a theoretical framework to predict the efficacy of quenching of electrical pulses in excitable media, such as those found in the human heart.
This breakthrough could significantly accelerate the development of more efficient defibrillation techniques for treating cardiac arrhythmias.
The study, published in Physical Review E, addresses a longstanding challenge in understanding how stable excitation waves in systems like cardiac tissue can be effectively neutralised through small changes.
These electrical waves, when irregular, are thought to underly serious conditions such as fibrillation, where the heart fails to pump blood effectively.
The research provides a way to predict the smallest possible interventions required to restore the system to a stable resting state and permit the normal rhythm to reassert itself.
The study bridges a crucial gap in understanding how to disrupt harmful excitation waves with minimal energy input, especially in the earliest stages of defibrillation through direct intervention.
Lead researcher Dr Christopher Marcotte of Durham University's Department of Computer Science said: "Predicting how small changes to carefully tuned states develop over time underlies much of our understanding of complex phenomena, from turbulence to weather; similar predictions for dynamically robust states, like fully developed electrical waves in the heart, requires further insight into the larger structures of these systems and how they interact.
"By predicting the boundaries for efficacious interventions in the propagation of these electrical waves, we provide additional tools for defibrillation researchers."
The team developed a linear theory capable of predicting 'quenching perturbations' - small changes that return an unstable system to its resting state.
This method improves upon traditional brute-force approaches by using computationally efficient semi-analytical techniques, inspired by similar approaches developed for the ignition — or starting excitation — of these waves.
This research focus on predicting suppression offers fresh insights into how to halt erratic electrical activity in tissues.
Using this framework, the researchers tested their predictions against various mathematical models of excitable media, including those simulating cardiac electrical activity.
The theory proved highly effective, showing qualitative and, in many cases, quantitative agreement with direct numerical simulations.
Defibrillation, the medical procedure to restore normal heart rhythms, typically involves applying a strong electrical shock to disrupt fibrillation.
This study opens the door to refining these techniques by targeting specific regions of the heart with smaller, more precise electrical pulses.
This could lower energy requirements, reducing the risk of tissue damage and making treatments more patient-friendly.
However, the researchers caution that quenching excitation waves is inherently more energy-intensive than initiating them as the latter rely on stored chemical energy in the tissue, which presents challenges for direct practical implementation.
Despite these challenges, the research findings lay the groundwork for innovations in low-energy defibrillation strategies and may augment emerging techniques like the Low-Energy Atrial Pacing (LEAP) method.
To encourage further exploration, the researchers have made their methodology and data openly available online. By providing access to their code, they hope to foster collaboration and spur additional advances in this critical area of medical science.
