Evaluating the association between cardiac and peripheral resistance arms of the baroreflex.

The study proposes an extension of cardiac baroreflex (cBR) sequence analysis, traditionally performed over spontaneous fluctuations of heart period and systolic arterial pressure, to typify peripheral resistance baroreflex (prBR) from spontaneous variations of peripheral resistances and diastolic arterial pressure. The prBR baroreflex sensitivity (BRS _prBR ) and percentage of prBR sequences (SEQ% _prBR ) were computed along with analogous quantities assessed over cBR (i.e. BRS _cBR and SEQ% _cBR ). The cBR and prBR were typified in healthy subjects at rest (REST) and during light bicycle ergometer exercise at 10 percent of the maximal effort (EXE). Both cBR and prBR were affected by EXE: indeed, BRS _cBR and SEQ% _prBR were significantly reduced. Moreover, while BRS _cBR and BRS _prBR were not significantly associated, SEQ% _cBR and SEQ% _prBR were, and the correlation coefficient was positive. This study suggests that prBR can be typified from spontaneous variabilities along with the more traditional cBR, thus enlarging the possibility of monitoring human cardiovascular control mechanisms.