Brachial Artery Pulsatility Index Change 1 Minute After 5-Minute Forearm Compression

Abstract

Objective. Endothelial impairment evaluation by sonographic measurement of flow‐mediated dilatation (FMD) has become broadly used. However, this method has 2 main caveats: the dilatation depends on the baseline arterial diameter, and a high precision level is required. Vasodilatation leads to an amplified fall in impedance. We hypothesized that assessment of the pulsatility index change (PI‐C) 1 minute after 5‐minute forearm compression might evaluate that fall in impedance. The aim of this study was to compare the PI‐C with FMD. Methods. Flow‐mediated dilatation and the PI‐C were assessed in 51 healthy women aged between 35.1 and 67.1 years. We correlated both FMD and the PI‐C with age, body mass index, waist circumference, cholesterol level, high‐density lipoprotein level, glucose level, systolic and diastolic blood pressure, pulse pressure, brachial artery diameter, simplified Framingham score, intima‐media thickness, and carotid stiffness index. Intraclass correlation coefficients between 2 FMD and PI‐C measurements were also examined. Results. Only FMD correlated with baseline brachial diameter (r = −0.53). The PI‐C had a high correlation with age, body mass index, waist circumference, cholesterol level, systolic blood pressure, pulse pressure, simplified Framingham score, and intima‐media thickness. The correlation between FMD and the PI‐C was high (r = −0.66). The PI‐C had a higher intraclass correlation coefficient (0.991) than FMD (0.836) but not brachial artery diameter (0.989). Conclusions. The PI‐C had a large correlation with various markers of cardiovascular risk. Additionally, PI‐C measurement does not require offline analysis, extra software, or electrocardiography. We think that the PI‐C could be considered a marker of endothelial function. However, more studies are required before further conclusions.

Melatonin improves endothelial function in vitro and prolongs pregnancy in women with early‐onset preeclampsia

“…To determine the maternal vascular response, if any, to melatonin administration we undertook arterial Doppler indices from the right brachial and bilateral uterine arteries at each predelivery time point using a Philips iU22 ultrasound machine (Philips Medical Systems, Bothell, WA, USA). Brachial artery pulsatility index (PI) change (PIC) was obtained using a Philips linear 5.0‐17.0 MHz probe (L17‐5) using previously described methods . Subjects rested for at least 10 minutes and were positioned in supine position with slight abduction of the right arm.…”

Reliability of sonographic measurements of endothelial function: Flow‐mediated dilation, blood flow velocity, resistive and pulsatility indices

“…Flow‐mediated dilation is technically challenging, and measurement errors, even if in fraction of millimetres, may affect the overall accuracy. Post‐cuff‐release change in diameter is usually about 0.2 mm in healthy individuals and even less in the presence of impaired FMD, which emphasises the need for maximum precision . Sorensen et al .…”

“…PI and RI add to the information on blood flow and vascular impedance, especially distal to the analysed point that cannot be obtained from velocity alone. We have used the Doppler indices to quantify peripheral resistance and spectral Doppler to assess flow velocity along with the more established FMD protocol for assessing vasodilation . This study aimed to compare inter‐rater and intra‐rater reliability of baseline, post‐cuff‐release and the percentage change between FMD, flow velocity, RI and PI techniques to determine the relative feasibility for use of each in research and/or clinical practice.…”

Pulsatility Index of Popliteal Artery in Patients with Isolated Calf Vein Thrombosis: A Novel Technique for Detecting Thrombosis

“…The PI is considered to be a sensitive index in differentiating vascular changes. It relates to arterial resistance of the vessels distal to the analyzed point [12]. The systolic acceleration time of the waveform is influenced by abnormalities proximal to the measurement site, whereas the decay of the velocity tends to relate to the distal circulation.…”