Analysis of endocardial micro-accelerometry during Valsalva maneuvers

The endocardial acceleration (EA) signal is a particular kind of cardiac mechanogram, acquired through a micro-accelerometer, 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.