Theoretical Aspects of Resting-State Cardiomyocyte Communication for Multi-Nodal Nano-Actuator Pacemakers

Abstract

The heart consists of billions of cardiac muscle cells—cardiomyocytes—that work in a coordinated fashion to supply oxygen and nutrients to the body. Inter-connected specialized cardiomyocytes form signaling channels through which the electrical signals are propagated throughout the heart, controlling the heart’s beat to beat function of the other cardiac cells. In this paper, we study to what extent it is possible to use ordinary cardiomyocytes as communication channels between components of a recently proposed multi-nodal leadless pacemaker, to transmit data encoded in subthreshold membrane potentials. We analyze signal propagation in the cardiac infrastructure considering noise in the communication channel by performing numerical simulations based on the Luo-Rudy computational model. The Luo-Rudy model is an action potential model but describes the potential changes with time including membrane potential and action potential stages, separated by the thresholding mechanism. Demonstrating system performance, we show that cardiomyocytes can be used to establish an artificial communication system where data are reliably transmitted between 10 s of cells. The proposed subthreshold cardiac communication lays the foundation for a new intra-cardiac communication technique.

Molecular Communication Aspects of Potassium Intracellular Signaling in Cardiomyocytes

“…The potential difference between the resting potential and the maximum membrane potential is set to 124 mV. Therefore, according to (7), the threshold number of the injected potassium ions is Q th = 2.30100 × 10 7 , and the maximum number of the injected potassium ions is Q max = 1.18885 × 10 8 .…”

“…In a concept of the multi-nodal leadless pacemaker which we have recently proposed [3], communication of sensed data and commands for current injections between synthetic cells or capsules placed in atrial or ventricle can be realized utilizing cardiomyocytes, thus enabling an alternative transmission pathway and connectivity which bypass the damaged natural conduction system. Intercellular cardiomyocyte signal transmission provides interesting insights into data transmission and scheduling using the cardiomyocyte system as a transmission channel without interrupting the natural, ongoing cell-to-cell communication needed for heart function [4]- [7]. In this regard, we have proposed and analyzed the resting-state (subthreshold) cardiomyocyte communication method within an intracardiac communication system [7].…”

“…Intercellular cardiomyocyte signal transmission provides interesting insights into data transmission and scheduling using the cardiomyocyte system as a transmission channel without interrupting the natural, ongoing cell-to-cell communication needed for heart function [4]- [7]. In this regard, we have proposed and analyzed the resting-state (subthreshold) cardiomyocyte communication method within an intracardiac communication system [7].…”

“…In the intracardiac communication system, a cardiomyocyte is an elementary building block, where ions such as sodium (Na + ), calcium (Ca 2+ ) and potassium (K + ) ions further play a crucial role in defining electrophysiological activity. This activity is, in turn, essential for encoding data via the subthreshold membrane potential fluctuations [7]. The ions are dynamically exchanged between the intracellular and extracellular space (Figure 1a), which leads to the creation of the ionic currents ( Figure 1b): sodium current (I Na ), slow inward calcium current (I Ca ), and potassium current (I K ), among others.…”

“…• analyze the potassium-based signaling (sub)-system, and • propose a novel way of associating the intracellularly transmitted ions with the membrane potential fluctuations relevant for encoding data via the resting-state cardiomyocyte communication method [7], [15]- [19].…”