Ambulatory measurement of pulsatile hemodynamics

Measurements of arterial stiffness and pulsatile hemodynamics undoubtedly led to enormous progress in our understanding of cardiovascular physiology, aging, and development of diseases. Until very recently, these measurements were confined primarily to research laboratories and hospitals and less to the doctor's office. In contrast, we know from the experience in hypertension that out-of-office measurements are key to a better understanding of hemodynamics (for instance, blood pressure [BP]) in individual subjects. Moreover, the variability of hemodynamic measurements (beat-to-beat, daytime-nighttime, and nighttime-early morning) seem to have a distinct physiological and pathophysiological role. In the very last years, technological progress facilitated ambulatory measurements not only of heart rate and brachial BP but also of central BP and pulsatile hemodynamics (measures of antegrade and reflected waves). Most of the devices used are automated oscillometric cuff-based sphygmomanometers, equipped with dedicated software for acquisition and processing of waveforms. The present article intends to provide an overview on available technologies, devices and their validation, important technical aspects, similarities and differences from 24-h profiles of heart rate and brachial BP, clinical applications and relationships with clinical outcomes.