Low Energy Defibrillation in Human Cardiac Tissue: A Simulation Study

Abstract

We aim to assess the effectiveness of feedback-controlled resonant drift pacing as a method for low energy defibrillation. Antitachycardia pacing is the only low energy defibrillation approach to have gained clinical significance, but it is still suboptimal. Low energy defibrillation would avoid adverse side effects associated with high voltage shocks and allow the application of implantable cardioverter defibrillator (ICD) therapy, in cases where such therapy is not tolerated today. We present results of computer simulations of a bidomain model of cardiac tissue with human atrial ionic kinetics. Reentry was initiated and low energy shocks were applied with the same period as the reentry, using feedback to maintain resonance. We demonstrate that such stimulation can move the core of reentrant patterns, in the direction that depends on the location of the electrodes and the time delay in the feedback. Termination of reentry is achieved with shock strength one-order-of-magnitude weaker than in conventional single-shock defibrillation. We conclude that resonant drift pacing can terminate reentry at a fraction of the shock strength currently used for defibrillation and can potentially work where antitachycardia pacing fails, due to the feedback mechanisms. Success depends on a number of details that these numerical simulations have uncovered.

Regional cooling facilitates termination of spiral-wave reentry through unpinning of rotors in rabbit hearts

“…8,9 Arguably, should SW reentry be regulatable by procedures other than DC shocks or those combined with low-energy shocks, it could lead to innovative therapeutic modalities for prevention of arrhythmic death. Although several conceptual approaches have been proposed to terminate SW reentry by low-energy DC application, e.g., resonant drift, 10,11 controlling chaos, 12 synchronized pacing, 13,14 and unpinning of SWs, 15,16 feasibility of these approaches has not yet been validated. In isolated rabbit hearts, we have previously shown that moderate hypothermia facilitates termination of VT through destabilization (unpinning) of SW reentry.…”

Phase Entrainment of Induced Ventricular Fibrillation: A Human Feasibility and Proof of Concept Study.

“…Bidomain theory [21] provides an approach to how stimulation from electrodes in or near the heart can excite and pace the myocardium, or defibrillate via the induction of virtual electrodes [22] . These theories have been used to design [23] and test methods to produce defibrillation by repetitive trains of small amplitude electrical stimuli, numerically [24,25] , in vitro, on cell cultured preparations and isolated perfused hearts, and in acute animal preparations [8, 26 -27] .…”

Performance evaluation of GPU parallelization, space‐time adaptive algorithms, and their combination for simulating cardiac electrophysiology

“…Even though the implementation and use of these models is a complex and difficult task, the applications and benefits justify their use. Computer models have been used during the tests of new drugs, development of new medical devices, and new techniques of noninvasive diagnosis for several cardiac diseases …”

“…Computer models have been used during the tests of new drugs, development of new medical devices, and new techniques of noninvasive diagnosis for several cardiac diseases. [1][2][3] To speed up cardiac simulations and to allow more precise and realistic ones, 2 different techniques have been traditionally exploited: parallel computing and sophisticated numerical methods. [4][5][6] These 2 research areas, parallel computing and numerical methods, are continuously evolving at a fast pace.…”