Power spectral analysis of RR variability.
The analysis of beat-to-beat spontaneous oscillations of heart rate variability is a recent and noninvasive approach capable of providing important information on neural mechanisms controlling cardiovascular function. In particular, with spectral analysis of RR variability, two major components can be detected at low (LF, approximately 0.1 Hz) and high (HF, approximately 0.25 Hz) frequency. They have been demonstrated to be appropriate indices of, respectively, sympathetic and parasympathetic modulations of heart period. In control subjects, at rest, LF is slightly predominant over HF. In post myocardial infarction patients there is a predominant LF and a diminished HF that suggests an alteration of sympatho-vagal balance with a predominance of sympathetic tone. This approach, by providing indices of sympathetic and vagal neural regulatory outflows, appears adequate to evaluate several pathophysiological conditions such as ischemic heart disease, hypertension or congestive heart failure, which are characterized by important alterations of neural regulatory mechanisms.
Lombardi
F
F
Istituto Ricerche Cardiovascolari, CNR, Ospedale L Sacco, Milano.
Malliani
A
A
D004562:Electrocardiography; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D009203:Myocardial Infarction / Q000503:physiopathology*