B-PO03-026 SYNCHRONIZATION BETWEEN CARDIAC INTERVALS IN HEALTHY SUBJECTS AND SUBJECTS WITH PACEMAKERS.

Abstract

The heart rate variability (HRV) makes it possible to maintain the homeostasis of the cardiovascular system, allowing its adaptation to multiple stimuli. Many studies have shown that cardiac pacing above 40% increases the risk of developing ventricular remodeling, with adverse consequences for the ejection fraction. This effect persists beyond the refinement achieved so far in these devices. In this work we show a possible cause for this persistence. To we show the desynchronization that occurs between the various stages of the cardiac cycle in patients with pacemakers due to the current design of these devices. We examined Holter recordings of healthy adult subjects with pacemakers. The time series of the various cardiac intervals were analyzed in the frequency domain. Figure 1a shows the synchronization of the cardiac cycle for healthy individuals. All the intervals that include the TP interval are synchronized with each other, have the same autocorrelation function, and the same cross-correlation function. The other subintervals are synchronized with each other so that the variability of the TP interval is transferred to the RR interval. Figure 1b,c shows the effect of a VVI pacemaker. The RR interval is set in a fixed duration, the RT interval is specific to the patient, and therefore the TR interval is altered. Figure 1d,e,f schematically shows the effect of the other types of pacemakers. Therefore, setting any cardiac subinterval alters the timing of the entire cardiac cycle. We show that the synchronization within the cardiac cycle is altered in current pacemakers. This temporal phenomenon is not related to stimulation sequence.