Analysis of Endocardial Micro:Accelerometry during Valsalva Maneuvers

Abstract

The endocardial acceleration (EA) signal is a particular kind of cardiac mechanogram, acquired through a microaccelerometer, embedded at the tip of a cardiac pacing lead, that can be chronically implanted inside a cardiac chamber. In this work, we analyze the evolution of the main EA-derived markers during severe cardio-respiratory modifications. Intracardiac electrograms (EGM), intraventricular pressure and EA data were acquired from 6 sheep during a set of Valsalva-like maneuvers. These data have been processed to segment the main EA components during each Valsalva phase, in a beat-to-beat basis. Results confirm the correlation between the energy of the EA1 component and the dP/dtmax. Significant modifications are observed in the main components of the EA signal during and just after the maneuver. These modifications may be useful for the characterization of respiratory events from the analysis of intracardiac EA signals.

Analysis of Cardiac Vibration Signals Acquired From a Novel Implant Placed on the Gastric Fundus

“…A Valsalvalike respiratory maneuver was applied during data acquisition in order to evoke hemodynamic modifications that can be observable from both acquisition sites. Data acquisition was performed acutely, under anesthesia, with ventilatorassisted respiration and consisted of one stage of continuous positive inspiratory pressure (CPP) of 30 cmH 2 O of 15 s duration, followed by a 10 s apnea at atmospheric pressure (Gallet et al, 2016). The main objective of this setup was to validate if the evolution of the markers obtained from the gastric and reference sites during the Valsalva-like maneuver are correlated.…”

“…Implantable systems may be a solution to this observability challenge. A number of studies have been focused on the acquisition of accelerometric signals to measure cardiac vibrations signals from inside the heart chambers in an invasive manner (Hernández et al, 2013;Gallet et al, 2016). These endocardial acceleration (EA) signals have two main components known as EA1 and EA2, which are associated with the first and second heart sounds, respectively.…”

“…In past works, our group has proposed methods for the acquisition and processing of cardiac mechanical signals from accelerometers embedded into the stimulation lead of cardiac implantable devices (Hernández et al, 2013;Gallet et al, 2016;Calvo et al, 2018). Although these developments have provided interesting results for the optimal handling of cardiac resynchronization therapy in HF patients, not all patients may benefit from an active cardiac implantable device (Ponikowski et al, 2016;Yancy et al, 2017).…”