Frequency-domain analysis of arterial blood pressure: a probe for central nervous system activity

Spontaneous, self-sustained arterial blood pressure oscillations (APO; Mayer-rhythm) were studied in dogs exposed to hypotension, hemorrhage, hypoxia, or cerebral ischemia. Frequency spectra analysis of APO revealed a large amplitude (15-30 mmHg), low frequency (0.04-0.06 Hz) component. Higher frequency peaks (f>0.1 Hz) of much lower power amplitude were associated with respiratory activity. These experimental pathophysiologic states resulted in the loss of broadband frequency spectra (observed in control studies) and the emergence of dominant bifurcating narrowband APO rhythms. The periodicities observed implicate a CNS-mediated neural pacemaker (i.e. sympathetic overdrive) in arterial pressure oscillations. >