Central Aortic Blood Pressure From Ultrasound Wall-Tracking of the Carotid Artery in Children

Abstract

Children aged 2 to 18 years (n=9) attending for diagnostic or interventional arteriography for the investigation/treatment of suspected renovascular disease or congenital heart disease were recruited from the Paediatric Nephrology and Cardiology departments at Evelina London Children's Hospital. Children with arrhythmias or clinical evidence of heart failure were excluded from the study. After standard preparations for arteriography, vascular access to the femoral artery was established with a homeostatic sheath. A 4-FR Abstract-Differences between central aortic root (c) and peripheral (p) systolic blood pressure (SBP) may be particularly marked in children, but noninvasive methods for assessing cSBP in children have not been validated. We compared estimates of cSBP obtained from radiofrequency ultrasound wall tracking of the carotid artery (ART.LAB system) with that measured directly by a catheter in the aortic root at the time of arterial cannulation. Carotid waveforms were calibrated from invasive measurements of mean and diastolic pressures. In 9 children aged 10.5±5.0 years (mean±SD), cSBP obtained from carotid wall tracking was highly correlated with invasive measures of cSBP (r=0.99) with mean (±SD) difference 3.9±2.5 mm Hg. Second, we compared values of cSBP obtained from the carotid with those obtained using noninvasive applanation tonometry at the radial artery and a radial-to-aortic transfer function (SphygmoCor). Both carotid and radial tonometric measurements were calibrated from the same peripheral mean and diastolic measurements of blood pressure obtained by sphygmomanometry. In 84 children aged 13.2±3.2 years, there was excellent agreement between the 2 methods (r=0.95; P<0.001) with mean difference 0.71±3.7 mm Hg (95% confidence interval =−1.53 to 1.01). This invasive validation study confirms that cSBP as estimated by carotid wall tracking provides an acceptable measurement of true cSBP when calibration is from true mean and diastolic pressures. Close agreement of cSBP obtained by carotid wall tracking and radial tonometry suggests that these provide similar results when calibrated from the same peripheral blood pressure measurements.

2016 European Society of Hypertension guidelines for the management of high blood pressure in children and adolescents

“…Compared with adults, this phenomenon differs significantly in children, whose SBP amplification is substantial, a mean ~20 mmHg, almost twice as in adults (82). If cSBP relates more closely than peripheral SBP to TOD, including LVH, as some claim in adults (83), it may be very useful clinically to estimate its values in children, but its benefit and independence from peripheral BP remains unknown.…”

Validation of Devices and Methods for Noninvasive Estimation of Central Aortic Blood Pressure in Children

“…We would like to congratulate Milne et al, 1 because they conducted this study, which covers a great gap about the validity and feasibility of devices for noninvasive estimation of central blood pressure (c-BP) in children. This will be a reference article and thus it is critical to clarify a few issues.…”

“…To better interpret the results of this study, 1 it would be useful to know what was the order of the exams (if not randomized): (1) applanation tonometry (SphygmoCor), (2) carotid wall tracking (ART.LAB), and (3) brachial BP measurement, in each study arm.…”

Elevated Ejection-Phase Myocardial Wall Stress in Children With Chronic Kidney Disease

“…Central aortic systolic pressure was measured noninvasively and, although we have recently validated a similar method in children, 22 there is inevitably some error in a noninvasive estimation of central systolic pressure. However, errors in estimation of central pressure are unlikely to have confounded our finding of increased wall stress because this resulted from a lower ratio of wall volume/cavity volume rather than an increase in pressure in children with CKD.…”