V.N. Biktashev, I.V. Biktasheva. Final Report: FEEDBACK CONTROL OF RESONANT DRIFT AS A TOOL FOR LOW VOLTAGE DEFIBRILLATION Background and context

Low-voltage defibrillation There are more than 100 thousand premature cardiac deaths every year in the UK alone. Most of these are associated with re-entrant cardiac arrhythmias. Milder forms of arrhythmias, such as paroxysmal tachycardia or atrial flutter, seriously decrease quality of life. The extreme form is the ventricle fibrillation, which is related to persistent re-entrant waves in the the larger chambers of the heart, and is usually lethal. The last line of defense against re-entrant arrhythmias and fibrillation is electrical defibrillation, which is a powerful electric shock, delivered transthoracically or by implanted devices, aiming at “resetting” all the excitable cells in the heart to the same state. Unfortunately, the defibrillation is not always effective, and causes collateral damage to the heart itself and surrounding tissues. Defibrillating shock is extremely painful, even with the implantable devices (transthoracic defibrillators usually are applied to unconscious patients as ventricular fibrillation causes loss of consciousness very quickly). Thus there is a high clinical demand on alternative methods of defibrillation which would work with smaller voltages. Such methods exist, e.g. overdrive pacing, and are sometimes attempted by the implantable devices or on the operating table, and the high-voltage shocks are delivered if the milder methods fail. Such milder methods, however, fail too often, so search for more efficient low-voltage defibrillation algorithms continues.