Repeatability of non-invasive measurement of intracerebral pulse wave velocity using transcranial Doppler

Abstract

In the present study, the repeatability of three techniques for measuring peripheral PWV (pulse wave velocity) has been studied. A transcranial Doppler provided a wave reading from the middle cerebral artery. Using the transit time between the R-wave of an ECG and the 'foot' of this wave we were able to calculate a PWV (PWV-brain). An ear clip transducer provided a pressure wave reading (PWV-ear). A third pressure reading came from a Finapres transducer on the left middle finger (PWV-finger). The PWV was calculated as distance between two points/transit time of the pulse wave. Eleven volunteers had three sets of readings averaged for each technique taken in two separate sessions. There was good agreement between observers for the mean PWV values, and good agreement for mean results in different sessions. The RC%s (repeatability coefficient percentages) for between-observer repeatability in each session were good and approximately equivalent for PWV-finger (5-7%) and PWV-brain (5-7%). The repeatability of the PWV-ear measurement was less satisfactory (8-18%). The RC% for the same observer between sessions was less good, being 11% for the PWV-finger, 16-17% for PWV-brain and 11-19% for PWV-ear. The RC%s for the inter-session inter-observer measurements were between 10.7-12.1% for the PWV-finger, 14.7-19.5% for PWV-brain and 8.3-15% for PWV-ear. The transit time RC%s were lower in most measurements. The between-observer repeatability of all measures was satisfactory. Owing to the less good repeatability on different occasions, the use of PWV-brain and PWV-ear will depend on the magnitude of differences to be expected.

Glymphatic solute transport does not require bulk flow

“…In contrast, Bilston and co-workers came to the conclusion that bulk flow is possible for short distension wavelengths of 20 to 300 μm and decreases as the wavelength increases. However, they did not extend their study to physiologic wavelengths, which are three to four orders of magnitude longer27. Our results show that under physiologic conditions, arterial pulsations alone are unlikely to produce notable bulk flow.…”

Influence of hyperglycemia during and after pregnancy on postpartum vascular function

“…Transit time was measured from the R-spike of the ECG to the foot of the finger blood pressure waveform from the Finometer fitted to the intermediate phalange of the middle finger in the same cardiac cycle. The distance between the sternal notch to the center of the intermediate phalange was measured along the surface of the body and PWV was calculated as distance/transit time (20,44).…”

Increased Cerebral Arterial Pulsatility in Patients With Leukoaraiosis

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