Schäfer A; Vagedes J
Arcim institute, Im Haberschlai 7, 70794 Filderstadt,
Germany; University of Tübingen, Institute of Medical
Psychology and Behavioral Neurobiology, Gartenstr. 29, 72074 Tübingen, Germany.
BACKGROUND:
The usefulness of heart rate variability (HRV) as a clinical research and
diagnostic tool has been verified in numerous studies. The gold standard
technique comprises analyzing time series of RR intervals from an
electrocardiographic signal. However, some authors have used pulse cycle
intervals instead of RR intervals, as they can be determined from a pulse wave
(e.g. a photoplethysmographic) signal. This option is
often called pulse rate variability (PRV), and utilizing it could expand the
serviceability of pulse oximeters or simplify
ambulatory monitoring of HRV.
METHODS:
We review studies investigating the accuracy of PRV as an estimate of HRV,
regardless of the underlying technology (photoplethysmography,
continuous blood pressure monitoring or Finapresi,
impedance plethysmography).
RESULTS/CONCLUSIONS:
Results speak in favor of sufficient accuracy when subjects are at rest,
although many studies suggest that short-term variability is somewhat
overestimated by PRV, which reflects coupling effects between respiration and
the cardiovascular system. Physical activity and some mental stressors seem to
impair the agreement of PRV and HRV, often to an inacceptable extent. Findings
regarding the position of the sensor or the detection algorithm are not
conclusive. Generally, quantitative conclusions are impeded by the fact that
results of different studies are mostly incommensurable due to diverse
experimental settings and/or methods of analysis.