Low energy defibrillation in human cardiac tissue: a simulation study

TL;DR

This study uses computer simulations to demonstrate that feedback-controlled resonant drift pacing can effectively terminate re-entrant cardiac arrhythmias at significantly lower energy levels than traditional defibrillation, potentially reducing side effects.

Contribution

It introduces a novel feedback-controlled resonant pacing method for low energy defibrillation, showing its effectiveness in a human cardiac tissue model.

Findings

Resonant drift pacing can move re-entrant patterns depending on electrode placement.

Low energy shocks can terminate re-entry at one-tenth the energy of conventional shocks.

Feedback mechanisms are crucial for the success of this low energy defibrillation approach.

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 ICD therapy where it is not tolerated today. We present results of computer simulations of a bidomain model of cardiac tissue with human atrial ionic kinetics. Re-entry was initiated and low energy shocks were applied with the same period as the re-entry, using feedback to maintain resonance. We demonstrate that such stimulation can move the core of re-entrant patterns, in the direction depending on location of electrodes and a time delay in the feedback. Termination of re-entry is achieved with shock strength one order of magnitude weaker than in conventional single-shock defibrillation. We conclude that resonant drift pacing can terminate re-entry 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 which these numerical simulations have uncovered. \emph{Keywords} Re-entry; Bidomain model; Resonant drift; ICD; Defibrillation; Antitachycardia pacing; Feedback.