Temporal Stability of Ambulatory Cardiovascular Monitoring

The existing literature on the temporal stability of cardiovascular ambulatory monitoring data is reviewed. These studies generally show adequate reproducibility across time for blood pressure mean levels. However, the existing data on the reproducibility of blood pressure variability suggest that conventional estimates of 24-hour variability, such as standard deviation, may be very unstable from one monitoring day to the next. Several approaches are suggested for improving the estimate of variability in ambulatory data. Preliminary attempts using these approaches suggest, in contrast to earlier findings, that the temporal stability of ambulatory variability may also be quite good. More studies are recommended that use newer monitors, report heart rate data, employ multiple analytic strategies, and investigate the role of activity and behavior in the temporal stability of ambulatory levels and variability.