Power spectral analysis of heart rate variability in psychiatry

Power spectrum analysis of heart rate variability (PSA of HRV) is a promisi ng method, which can be used as an index of cardiac autonomic balance. PSA of HRV is a noninvasive technique, based on ECG sampling of RR interval var iation, thus providing a dynamic assessment of sympathetic and parasympathe tic tone, reflecting the interactions between the two. It has been shown to have potential value in various laboratory and clinical conditions. It is influenced by many factors such as age, sex, position, breathing, smoking, hour of the day and medications. Different methods of data processing by va rious authors have often elicited conflicting results. Standard values are not yet available to be used or compared in different settings. From the in terest it has raised, it may be expected that this method will be in widesp read use in clinical practice in the future, providing a useful toot, both for diagnostic and prognostic purposes, as well as serving as a further aid towards monitoring therapeutic interventions. This review highlights techn iques of dynamic assessment of HRV and studies of its clinical applications in psychiatry in particular. It raises the potentially important prognosti c implications of protracted autonomic dysfunction in psychiatric patient p opulations, especially for cardiovascular morbidity and mortality.