A LEAP in controlling cardiac fibrillation

Researchers develop a new low-energy defibrillation method

July 14, 2011

An international team of scientists from the Max-Planck-Institute for Dynamics and Self-Organization (Göttingen, Germany), Cornell University (Ithaca, New York) the Ecole Normale Supérieure de Lyon (France), the University Medicine Göttingen (Germany), the Rochester Institute of Technology (USA), and the Institut Non-Linéaire de Nice (France) have developed a new low-energy method for terminating life-threatening cardiac fibrillation of the heart. They have shown that their new technique called LEAP (Low-Energy Anti-fibrillation Pacing) reduces the energy required for defibrillation by more than 80% as compared to the current conventional method. Their discovery opens the path for the painless therapy of life threatening cardiac fibrillation. The scientists describe their results in the current issue of Nature.

The new method terminates the turbulent electric activity within the heart step by step. "Our most important allies are natural heterogeneities within the heart such as blood vessels, fatty tissue or fibrotic tissue", says Eberhard Bodenschatz from the Max Planck Institute. In experiments and computer simulations the researchers were able to show that these heterogeneities can act as the origins for synchronizing waves. "Quite weak electrical pulses suffice to stimulate the cells in these regions", says Alain Pumir from Lyon. With every additional pulse more heterogeneities are activated, thus gradually suppressing chaotic activity.  "The heterogeneities act as small control sites that – once activated – can 'reprogram' the entire organ", adds Valentin Krinsky from Nice.

In principle, the results also apply for defibrillation of ventricular fibrillation, a life-threatening arrhythmia, which is terminated only by external and implantable defibrillators. For a large number of patients wearing implantable cardioverter-defibrillators (ICD) the new technique may eliminate pain, improve the success rate of treatment, prolong battery life and therefore reduce the need for surgical device exchanges.

"The development of LEAP is a groundbreaking result and an outstanding example of successful interdisciplinary collaboration between physicists and physician-scientists, with immediate impact on the development of novel therapies for life-threatening cardiac arrhythmias", says Markus Zabel from the University Center Göttingen. The ideas leading to LEAP were first developed by asking elementary physical questions about the interaction between electric field and cardiac tissue; the results of earlier theoretical work in physics, in particular in the French National Center for Scientific Research (CNRS), may be finding their way to clinics. Indeed, "we are working to get this to the patient as fast as possible", adds Gerd Hasenfuss, the head of the Heart Center Göttingen.

This work was supported by the Max Planck Society, the National Science Foundation (#0800793 and #0926190); the National Institutes of Health; by IFCPAR; by BMBF; by the Kavli Institute for Theoretical Physics and by the European Community's Seventh Framework Programme FP7/2007–2013 through HEALTH-F2-2009-241526 (EUTrigTreat).