Estimating central SBP from the peripheral pulse: influence of waveform analysis and calibration errorGuilcher, Antoinea; Brett, Sallya; Munir, Shahzadb; Clapp, Brianb; Chowienczyk, Philip JaJournal of Hypertension: July 2011 - Volume 29 - Issue 7 - p 1357–1366 doi: 10.1097/HJH.0b013e3283479070 Original papers: Blood vessels Buy Abstract Author InformationAuthors Article MetricsMetrics Objective To compare estimation of central cSBP by application of a generalized transfer function (GTF) to a peripheral arterial waveform and from the late systolic shoulder (SBP2) of such a waveform and assess errors introduced by noninvasive calibration of the waveform. Methods The digital arterial pulse was acquired noninvasively with a servo-controlled finger cuff. A high fidelity pressure tipped catheter was placed in the proximal aortic root. Measurements were made at baseline (n = 40), after nitrovasodilation, handgrip exercise (n = 18) and during pacing (n = 10). Estimates of cSBP obtained using a GTF and from SBP2 (using an algorithm applied to individual cardiac cycles) of the digital arterial waveform were compared with values measured at the aortic root. Results When arterial waveforms were calibrated from aortic intra-arterial mean and DBP there was close agreement between estimated and measured cSBP: mean difference between estimated and measured cSBP (SD): 1.0 (5.7) and −0.7 (5.5) mmHg for GTF and SBP2, respectively. Noninvasive oscillometric calibration increased variability in estimation of cSBP [mean difference, 1.3 (11) mmHg for SBP2] but estimates of the cSBP to peripheral systolic pressure increment from oscillometric calibration of SBP2 agreed well with those obtained using invasive calibration [mean difference −2.4 (6.1) mmHg]. Conclusion SBP2 potentially provides a simple measure of cSBP and is of comparable accuracy to a GTF. Noninvasive calibration increases variability for both methods but has less effect on the cSBP to peripheral SBP increment. aDepartment of Clinical Pharmacology, UK bDepartment of Cardiology, King's College London British Heart Foundation Centre, St Thomas' Hospital, London, UK Received 23 December, 2010 Revised 2 March, 2011 Accepted 6 April, 2011 Correspondence to Professor Phillip J. Chowienczyk, Department of Clinical Pharmacology, St Thomas' Hospital, Lambeth Palace Road, London SE1 7EH, UK Tel: +44 207 1884642; fax: +44 207 4012242; e-mail: email@example.com © 2011 Lippincott Williams & Wilkins, Inc.