image: High frequency alternating current electric fields slows then terminates an arrhythmia in a monolayer of cardiac tissue. The top set of frames shows snapshots of optical map of the electrical activity, and the bottom panel is the electrical activity at the site marked “x” in the optical map frames. A spiral wave (rapid arrhythmia) was initiated in the cardiac tissue. After one second, a high frequency electric field is applied, and the strength of the field gradually increases with time. The arrhythmia gradually slows down, and eventually terminates. After the field is turned off, no electrical activity is present. This shows that with increasing high frequency field strength, propagation speed in the tissue progressively slows until it ceases completely, but the effect disappears as soon as the high frequency field is turned off. This image is Figure 2B from the paper. This image relates to a paper that appeared in the Sept. 28, 2011, issue of Science Translational Medicine, published by AAAS. The paper, by Dr. Hari Tandri of Johns Hopkins University in Baltimore, Md., and colleagues, was titled, "Reversible Cardiac Conduction Block and Defibrillation with High-Frequency Electric Field." view more
Credit: Image courtesy of <i>Science</i>/AAAS