Low-Energy Defibrillation Using Resonant Drift Pacing

2008

Resonant drift of re-entry occurs in response to repetitive stimulation with period equal to that of the re-entry. Feedback controlled resonant drift drives re-entry out from excitable tissue, so may be used as antiarrthymic or defibrillation strategy. To test it in realistic computer simulations, we used monodomain and bidomain description of the tissue, rectangular 2D and 3D geometry, and anatomically realistic rabbit ventricles geometry, with Barkley, Drouhard-Roberge-Beeler-Reuter, and Courtemanche-Ramirez-Nattel kinetics models. Re-entries terminated at a fraction of the conventional shock strength. The success depends on the detailes of the feedback protocol. The simulations motivate experimental testing of the proposed low-voltage defibrillation method, which will be most productive in conjunction with simulations.

Biophysical Journal, 2009

We aim to assess the effectiveness of feedback controlled resonant drift pacing as a method for low energy defibrillation.

Biology

Cardiac pacing technologies have been implemented during the last few decades, including leadless pacemakers and pacing of the conduction system, such as His bundle pacing and left bundle branch area pacing [...]

IEEE Engineering in Medicine and Biology Magazine, 2000

The problem of battery self-discharge tensity at which a response occurs is the Cordis Research Corporation was initially believed solved by radioisotop-threshold for the prevailing situation. and ic power sources, but by the early 1970's, The "all or nothing" principle also ap-ALAN D BRSEI E S D the availability of high-energy-density bat-plies to systems, or syncytia, of cells, such

Circulation. Arrhythmia and electrophysiology, 2015

A kl d Bi i i t e SUNY NY Y U U Ups ps ps p ta t t te e e e M Medical University, Syrac ac acus u u e, NY; 2 Auckla a a and n n n Bioengineering te e e, e A A Au A ckland d d, N Ne N w w w w Ze Ze Ze Z al al a a an an a and; 3 3 3 C C C Cu urr rent t A A Addr dress s s s: : : Inst st st s itu u ute e e for r r T Tran an an ans s slat t tio io iona na nal l l Sc Sc Sc S ie ie ie ien nc n n e

Cardiac Bioelectric Therapy

Chaos: An Interdisciplinary Journal of Nonlinear Science, 2007

In this review article, we describe turbulence control in excitable systems by using a local periodic pacing method. The controllability conditions of turbulence suppression and the mechanisms underlying these conditions are analyzed. The local pacing method is applied to control Winfree turbulence ͑WT͒ and defect turbulence ͑DT͒ induced by spiral-wave breakup. It is shown that WT can always be suppressed by local pacing if the pacing amplitude and frequency are properly chosen. On the other hand, the pacing method can achieve suppression of DT induced by instabilities associated with the motions of spiral tips while failing to suppress DT induced by the instabilities of wave propagation far from tips. In the latter case, an auxiliary method of applying gradient field is suggested to improve the control effects. The implication of this local pacing method to realistic cardiac defibrillation is addressed.

Scholarena Journal of Biotechnology, 2017

Background: The electrical field (E-field) of the biventricular (BV) stimulation is important for the success of cardiac resynchronization therapy (CRT) in patients with cardiac insufficiency and widened QRS complex. The 3D modelling allows the simulation of CRT and high frequency (HF) ablation. Purpose: The aim of the study was to model different pacing and ablation electrodes and to integrate them into a heart model for the static and dynamic simulation of atrial and BV stimulation and high frequency (HF) ablation in atrial fibrillation (AF). Methods: The modelling and simulation was carried out using the electromagnetic simulation software CST (CST Darmstadt). Five multipolar left ventricular (LV) electrodes, one epicardial LV electrode, four bipolar right atrial (RA) electrodes, two right ventricular (RV) electrodes and one HF ablation catheter were modelled. Selected electrodes were integrated into the Offenburg heart rhythm model for the electrical field simulation. The simulation of an AV node ablation at CRT was performed with RA, RV and LV electrodes and integrated ablation catheter with an 8 mm gold tip. Results: The right atrial stimulation was performed with amplitude of 1.5 V with a pulse width of 0.5. The far-field potentials generated by the atrial stimulation were perceived by the right and left ventricular electrode. The far-field potential at a distance of 1 mm from the right ventricular electrode tip was 36.1 mV. The far-field potential at a distance of 1 mm from the left ventricular electrode tip was measured with 37.1 mV. The RV and LV stimulation were performed simultaneously at amplitude of 3 V at the LV electrode and 1 V at the RV electrode with a pulse width of 0.5 ms each. The far-field potentials generated by the BV stimulations could be perceived by the RA electrode. The far-field potential at the RA electrode tip was 32.86 mV. AV node ablation was simulated with an applied power of 5 W at 420 kHz and 10 W at 500 kHz at the distal 8 mm ablation electrode. Conclusions: Virtual heart and electrode models as well as the simulations of electrical fields and temperature profiles allow the static and dynamic simulation of atrial synchronous BV stimulation and HF ablation at AF. The 3D simulation of the electrical field and temperature profile may be used to optimize the CRT and AF ablation.

Procedia Computer Science, 2017

Spiral waves in the heart underlie dangerous cardiac arrhythmias such as fibrillation. Low-voltage defibrillation and cardioversion are modern methods to treat such pathologies. This type of electrotherapy is based on the phenomenon of superseding spiral waves by a high-frequency source of excitation. In this paper, we numerically simulated the superseding process in a thin layer of the cardiac muscle. We captured the case of a sole spiral wave with a stable core at the centre of a square. We used different cell-level models as well as a variety of electrode configurations and studied the induced drift of the spiral wave. Regimes of the external stimulation were classified based on whether they provide an effective and safe, that is without break-up, way to shift the spiral toward the boundary.

IEEE Reviews in Biomedical Engineering, 2011

Cardiac defibrillation, as accomplished nowadays by automatic, implantable devices (ICDs), constitutes the most important means of combating sudden cardiac death. While ICD therapy has proved to be efficient and reliable, defibrillation is a traumatic experience. Thus, research on defibrillation mechanisms, particularly aimed at lowering defibrillation voltage, remains an important topic. Advancing our understanding towards a full appreciation of the mechanisms by which a shock interacts with the heart is the most promising approach to achieve this goal. The aim of this paper is to assess the current state-of-the-art in ventricular defibrillation modeling, focusing on both numerical modeling approaches and major insights that have been obtained using defibrillation models, primarily those of realistic ventricular geometry. The paper showcases the contributions that modeling and simulation have made to our understanding of the defibrillation process. The review thus provides an example of biophysically based computational modeling of the heart (i.e., cardiac defibrillation) that has advanced the understanding of cardiac electrophysiological interaction at the organ level and has the potential to contribute to the betterment of the clinical practice of defibrillation.