TVI in RV configuration is the trans-valvular impedance derived between endocardial electrodes positioned in right atrium and ventricle. The RV-TVI increases in systole and decreases in diastole, following the time-course of RV contraction and relaxation.
TVI signal amplitude and morphology reflect the mechanical performance of the heart.
The comparison of averaged TVI waveforms recorded as a function of the VV delay indicates the best stimulation timing.
The LV-TVI is the impedance derived between right atrium and the cardiac vein containing the LV pacing lead. The LV-TVI decreases in systole and increases in diastole. The diastolic rise back to baseline outlines the progress of LV relaxation.
The lag between RV- and LV-TVI waveforms reflects the interventricular desynchronization. The stimulation timing should be aimed at the best synchronization of RV- and LV-TVI signals.
High flexibility in biventricular pacing with device autoregulation
Sensing and pacing parameters setting in 3 independent chambers, with the optional application of an interventricular delay and selection of the ventricle to be stimulated first. If required, pacing in the 2nd ventricle can be inhibited by electrical sensing on the corresponding channel. This allows a safety Hisian stimulation. The pacemaker is able, in fact, to provide a back-up stimulus in the right ventricle apex, in case of Hisian ineffective stimulation.
Ejection check after ventricular pacing function with automatic adjustment of pacing energy in case of capture loss
Ejection check after ventricular sensing algorithm with an automatic safety pacing in case of external interferences