Arterial blood pressure and heart period relationships duringperiodic breathing in chronic heart failure patients

摘要

Periodic breathing (PB) is highly prevalent (>60%) in awakechronic heart failure (CHF) patients with moderate to severe symptomsand poor ventricular function. In this study, the authors analyzed byspectral techniques the variability of systolic (SAP) and diastolic(DAP) arterial pressure and their relationship with the variability ofthe heart period (HP) in 20 resting CHF patients with stable PB. Therelationship between instantaneous lung volume (ILV) and SAP and theassociation between the phase shift SAP-HP and baroreflex sensitivity(BRS) were also investigated. All signals showed a narrowband very lowfrequency (VLF) component about 0.02 Hz (the frequency of PB) whichexplained 38% (22) (median (quartile range)) of ILV variance, 74% (33)of HP, 86% (15) of SAP and 72% (21) of DAP. The coherence and phase atthe VLF peak were 0.76 (0.2) and -56° (41) for ILV-SAP, 0.71 (0.2)and -149° (52) for SAP-HP and 0.77 (0.3) and -191° (38) forDAP-HP. The correlation coefficient between the phase shift SAP- HP andBRS at the VLF peak was 0.78 (p<0.001). This study demonstrates thatduring PB in CHF, both the respiratory and cardiovascular controlsystems are entrained by the same VLF rhythm which explains most of thevariability of cardiovascular parameters. The VLF oscillation of SAPfollows the corresponding oscillation of HP but they change in theopposite direction. The shift depends on the functioning of thebaroreflex