Dual-sided Mapping During Global Stretch Using a Custom Miniaturized Endocardial Balloon with a Multipurpose Multichannel Acquisition System for Preclinical Electrophysiological Studies.

Acute regional myocardial stretch (STR) is known to induce myocardial electrophysiological modifications via mechano-electric feedback (MEF), including abnormal repolarization, premature excitation and increased complexity of activation leading to the initiation, maintenance and acceleration of arrhythmic events. Due to technical limitations little is known about intramural and endo-epicardial (ENDO-EPI) phenomena during these events. Understanding ENDO-EPI modifications produced by STR through MEF may require a dual-sided approach to simultaneously correlate macroscopic surface modifications and their independent or interconnected components. For that purpose, we optically mapped (OM) the EPI LV-surface, and developed a miniaturized multifunctional array balloon (MEAb) for ENDO mapping of small-to-mid sized hearts using a custom-developed scalable FPGA-based multichannel acquisition system (cMCAS). Our aim was two-fold to validate 1) the quality of the sub-endocardial electrograms (EGM) and its association to EPI voltage-transients; and, 2) to study the modifications produced by moderate STR on normal and abnormal activation. ENDO-EPI differences found in restitution properties could be implicated in STR-driven VF-mechanisms.