Guidelines for blood pressure measurement: development over 30 years.

In the last 2 decades, several scientific societies have published specific guidelines for blood pressure (BP) measurement, providing detailed recommendations for office, home, and ambulatory BP monitoring. These documents typically provided strong support for using out-of-office BP monitoring (ambulatory and home). More recently, several organizations recommended out-of-office BP evaluation as a primary method for diagnosing hypertension and for treatment titration, with office BP regarded as a screening method. Efforts should now be directed towards making ambulatory and home BP monitoring readily available in primary care and ensuring that such measurements are obtained by following current guidelines. Moreover, it should be mandatory for all published clinical research papers on hypertension to provide details on the methodology of the BP measurement.

Achieving reliable blood pressure measurements in clinical practice: It's time to meet the challenge.

A summary of statements for blood pressure (BP) measurement in the evaluation of hypertension in the 21st century by 25 international experts is provided. The status of office, home and ambulatory BP measurement techniques are discussed. Office BP measurement, whether automated (preferred), or otherwise, should only be used as a screening measurement, and diagnostic decisions for the initiation and titration of drug treatment should be based on out-of-office measurements (ambulatory or home). The hardware and software requirements and the adaptations of BP measuring devices to record other cardiovascular functions, such as arrhythmias, and adaptations for smartphone use and for electronic transmission are discussed. Regulatory bodies are urged to make accuracy and performance assessment mandatory before marketing BP measuring devices. The legal implications of manufacturing inaccurate devices are noted.

The pioneer in hemodynamics and pulse-wave analysis, Otto Frank.

Arterial pulse-wave velocity is a noninvasive index of arterial distensibility now generally advocated to assess cardiovascular health above-and-beyond merely measuring blood pressure. A host of recent findings supports its use. This evidence draws attention to the fact that vascular stiffness precedes the increase in blood pressure with age and that even nonpharmacological lifestyle interventions can improve distensibility independent of blood pressure. Where do these ingeniously modern ideas come from, and who defined the principles we embrace today? A worthwhile lesson in physiology and exercise in humility is the effort to revisit the origins of these concepts and the man to whom gratitude should be directed.

Continuous Blood Pressure Measurement From Invasive to Unobtrusive: Celebration of 200th Birth Anniversary of Carl Ludwig.

The year 2016 marks the 200th birth anniversary of Carl Friedrich Wilhelm Ludwig (1816-1895). As one of the most remarkable scientists, Ludwig invented the kymograph, which for the first time enabled the recording of continuous blood pressure (BP), opening the door to the modern study of physiology. Almost a century later, intraarterial BP monitoring through an arterial line has been used clinically. Subsequently, arterial tonometry and volume clamp method were developed and applied in continuous BP measurement in a noninvasive way. In the last two decades, additional efforts have been made to transform the method of unobtrusive continuous BP monitoring without the use of a cuff. This review summarizes the key milestones in continuous BP measurement; that is, kymograph, intraarterial BP monitoring, arterial tonometry, volume clamp method, and cuffless BP technologies. Our emphasis is on recent studies of unobtrusive BP measurements as well as on challenges and future directions.

[Ludwig Wittgenstein (1889-1951) and the "wound shock"]. / Ludwig Wittgenstein (1889-1951) et le "wound shock".

Ludwig Wittgenstein was born in 1889 in Vienna. As a scholar in Cambdrige University, his philosophical achievements are still major regarding the foundations of mathematics and language. In 1939, he took a job as a porter at London Guys' Hospital then under the Blitz. Wittgenstein met Drs. Grant and Reeve who worked in a dedicated "traumatic shock" under the auspices of the Medical Research Council unit, a unit which then moved to the Royal Victoria Infirmary in Newcastle; Wittgenstein followed them as a technician and improved the preparation of fine pieces of histology fixed by paraffin. He also invented a new device to record pulse pressure and paradoxical pulse search in laboratory rats. At the end of the war, he returned to Cambridge until 1949 and died in 1951.

Korotkoff sounds -- the improbable also occurs.

Very few discoveries have had such a large impact on and relevance to clinical medicine as the noninvasive measurement of the diastolic blood pressure. A number of gifted physiologists and clinicians were ineffectively in search of a noninvasive method to determine the diastolic pressure. Nonetheless, the quantification of the diastolic BP was not achieved by any of these clinical or physiological researchers, but by an unlikely and unexpected figure: Nikolai Sergeevich Korotkoff (1874-1920), a young Russian army surgeon, working under precarious conditions in the hardship of diverse wars. It is easy to dismiss the achievement of Korotkoff as a serendipitous discovery, similar to that of Alexander Fleming in the discovery of penicillin. However, Nassim N. Taleb's recent black swan theory may serve to illustrate his discovery in a new and, perhaps, surprising way.

From the first spectral analysis of blood pressure variability in the world to the present time: contribution of the Department of Physiology of the Faculty of Medicine, Masaryk University, Brno.

The review shows the significance of blood pressure regulation studies conducted during several decades at the Department of Physiology, Faculty of Medicine, Masaryk University, Brno. Continuous non-invasive blood pressure measurement was first introduced and patented here and, with the obtained data, the first spectral analysis of blood pressure was performed. This method was used in many different physiological studies on the relationship of blood pressure regulation to circulatory parameters, breathing, and baroreflex sensitivity. The article deals with studies on risk stratification of sudden cardiac death according to decreased baroreflex sensitivity, 24-hour heart rate variability, the amount of extrasystoles and late potentials. Importance of the new method of determination of one summation risk index is described here. A summary of the new conception of the relationship between low baroreflex sensitivity and hypertension is presented. Here, not only pathological changes of the vessel wall but also increased sympathetic activity and genetic predisposition play a role. Importance of studies conducted in young adults is highlighted, as inherited BRS decrease contributes to earlier blood pressure increase in the young. This research is highly topical, since prevention of hypertension in childhood is possible. Recent studies are dedicated to blood pressure regulation in young diabetics.

Non-invasive continuous blood pressure monitoring: a review of current applications.

Blood pressure monitoring has come a long way from the initial observations made by Reverend Hales in the 18th century. There are none that deny the importance of monitoring perioperative blood pressure; however, the limited ability of the current prevalent technology (oscillometric blood pressure monitoring) to offer continuous blood pressure measurements leaves room for improvement. Invasive monitoring is able to detect beat-to-beat blood pressure measurement, but the risks inherent to the procedure make it unsuitable for routine use except when this risk is outweighed by the benefits. This review focuses on the discoveries which have led up to the current blood pressure monitoring technologies, and especially the creation of those offering non-invasive but continuous blood pressure monitoring capabilities, including their methods of measurement and limitations.

[Riva-Rocci and blood pressure]. / Riva-Rocci en de bloeddruk.

Scipione Riva-Rocci (1863-1937) was educated in Turin as a physician and later as a doctor of internal medicine. In 1896 and 1897 he published a series of four articles (in Italian) on a new method for measuring blood pressure. Previous non-invasive methods were all based on compression of the radial pulse, in keeping with centuries of medical tradition, but they were cumbersome and unreliable. Riva-Rocci's innovation consisted in compressing the brachial artery instead, at the level of the upper arm. For this purpose he devised an inflatable rubber tube, which was rigid on the outside. Disappearance of the radial pulse on palpation indicated the systolic arterial pressure, as Riva-Rocci confirmed by calibration experiments in animals and with human cadavers. His instrument was introduced world-wide after a chance visit by the American neurosurgeon Harvey Cushing (1869-1939). The Russian surgeon Nikolai Korotkoff (1874-1920) was the first to apply auscultation of the artery below the cuff (in 1905), a method that allowed determination of diastolic arterial pressure. Riva-Rocci was Chief of Medicine at the municipal hospital in Varese from 1900 to 1928, where he developed a special interest in paediatrics.

Pulse wave analysis as an experimental tool to clinical application: past and present (review).

Pulse examination by palpation of a peripheral artery against a bony prominence is the most commonly used and widely accepted method. However this is subjective and thus prone to errors. Although pulse waveform was recorded in the 19th century, it did not gain popularity because of inconvenience in using the recording instruments and the absence of a sound theory to explain the wave forms recorded. Sphygmomanometry for recording blood pressure gained popularity as it was easy to record and had a sound theoretical background. Sphygmomanometry provides two extreme values of blood pressure but does not give a true representation of the blood pressure changes occurring in the entire cardiac cycle. Recently there has been resurgence in the analysis of the graphical recording of the pulse wave. Photoplethysmography is becoming a widely accepted technique in assessing the volume pulse. The whole review is about historical background, non-invasive methods of pulse recording, relation of the digital volume pulse to the pressure pulse and the advantages of recording the pressure pulse.

Arterial blood pressure measurement and pulse wave analysis--their role in enhancing cardiovascular assessment.

The most common method of clinical measurement of arterial blood pressure is by means of the cuff sphygmomanometer. This instrument has provided fundamental quantitative information on arterial pressure in individual subjects and in populations and facilitated estimation of cardiovascular risk related to levels of blood pressure obtained from the brachial cuff. Although the measurement is taken in a peripheral limb, the values are generally assumed to reflect the pressure throughout the arterial tree in large conduit arteries. Since the arterial pressure pulse becomes modified as it travels away from the heart towards the periphery, this is generally true for mean and diastolic pressure, but not for systolic pressure, and so pulse pressure. The relationship between central and peripheral pulse pressure depends on propagation characteristics of arteries. Hence, while the sphygmomanometer gives values of two single points on the pressure wave (systolic and diastolic pressure), there is additional information that can be obtained from the time-varying pulse waveform that enables an improved quantification of the systolic load on the heart and other central organs. This topical review will assess techniques of pressure measurement that relate to the use of the cuff sphygmomanometer and to the non-invasive registration and analysis of the peripheral and central arterial pressure waveform. Improved assessment of cardiovascular function in relation to treatment and management of high blood pressure will result from future developments in the indirect measurement of arterial blood pressure that involve the conventional cuff sphygmomanometer with the addition of information derived from the peripheral arterial pulse.