Spectral analysis of heart rate and blood pressure variability.

The cardiovascular system contains negative feedback and time-delay mechanisms resulting in oscillations in heart rate and blood pressure, which are apparent when these signals are measured over time. Specifically, spectral analysis and nonlinear analysis techniques allow quantification of heart rate and blood pressure variability. Alterations in heart rate and blood pressure variability as evidenced from the spectral characteristics of these physiological signals allow the clinicians to have indicators of aberrations of neural control in various conditions or when drugs such as beta blockers, adrenergic agents, methylxanthines, etc., are being administered.