REGULATION/DYSREGULATION in BLOOD PRESSURE Blood pressure – the most important parameter in cardiovascular system – „high-profile“ parameter •Blood pressure (BP) – pressure of the blood to the wall of the vessels • •Systolic BP, diastolic BP, pulse pressure, mean arterial pressure (MAP) • •BP = CO x R CO – cardiac output, R – resistance • •CO = SV x HR SV – stroke volume, HR – heart rate • Czech proverb says: repetition is the mother of wisdom…we will talk about basic characteristics of blood pressure: ESH AND ESC GUIDELINES 2013 ESH/ESC Guidelines for the management of arterial hypertension The Task Force for the management of arterial hypertension of the European Society of Hypertension (ESH) and of the European Society of Cardiology (ESC) Authors/Task Force Members: Giuseppe Mancia (Chairperson) (Italy) * , Robert Fagard (Chairperson) Classification BP values category Systolic BP Diastolic BP (mmHg) (mmHg) optimal < 120 < 80 normal 120 – 129 80 – 84 high normal pressure 130 – 139 85 – 89 Hypertension - mild 140 – 159 90 – 99 Hypertension - moderate 160 – 179 100 – 109 Hypertension - severe ≥ 180 ≥ 110 Isolated systolic hypertension ≥ 140 < 90 According the Guidelines of European Society of Cardiology 2013 2018 ESC/ESH Guidelines for the management of arterial hypertension The Task Force for the management of arterial hypertension of the European Society of Cardiology (ESC) and the European Society of Hypertension (ESH) Authors/Task Force Members: Bryan Williams* (ESC Chairperson) (UK), Giuseppe Mancia* (ESH Chairperson) (Italy), Wilko Spiering (The Netherlands), Enrico Agabiti Rosei (Italy), Michel Azizi (France), Michel Burnier (Switzerland), Denis L. Clement (Belgium), Antonio Coca (Spain), Giovanni de Simone (Italy), Anna Dominiczak (UK), Thomas Kahan (Sweden), Felix Mahfoud (Germany), Josep Redon (Spain), Luis Ruilope (Spain), Alberto Zanchetti† (Italy), Mary Kerins (Ireland), Sverre E. Kjeldsen (Norway), Reinhold Kreutz (Germany), Stephane Laurent (France), Gregory Y. H. Lip (UK), Richard McManus (UK), Krzysztof Narkiewicz (Poland), Frank Ruschitzka (Switzerland), Roland E. Schmieder (Germany), Evgeny Shlyakhto (Russia), Costas Tsioufis (Greece), Victor Aboyans (France), and Ileana Desormais (France) European Heart Journal (2018) 39, 3021–3104 •Classification of BP •It is recommended that BP be classified as •optimal, normal, high–normal, or grades •1–3 hypertension, according to office BP. •Changes in recommendations •2013 •Diagnosis: Office BP is recommended for screening and diagnosis of hypertension. • •2018 •Diagnosis: It is recommended to base the diagnosis of hypertension on: •Repeated office BP measurements; or Out-of-office BP measurement with ABPM and/or HBPM if logistically and economically feasible. •Treatment thresholds •2013 •Highnormal BP (130–139/85–89 mmHg): Unless the necessary •evidence is obtained, it is not recommended to initiate antihypertensive drug therapy at high–normal BP. •2018 •Highnormal BP (130–139/85–89 mmHg): Drug treatment may be •considered when CV risk is very high due to established CVD, especially •CAD. •Definitions of hypertension according to •office, ambulatory, and home blood pressure levels •Category SBP(mmHg) DBP(mmHg) •Office BPa >_140 and/or >_90 •Ambulatory BP • Daytime (or awake) mean >_135 and/or >_85 • Night-time (or asleep) mean >_120 and/or >_70 • 24 h mean >_130 and/or >_80 •Home BP mean >_135 and/or >_85 • •BP = blood pressure; DBP = diastolic blood pressure; SBP = systolic blood •pressure. •aRefers to conventional office BP rather than unattended office BP. Regulatory mechanisms for blood pressure are targets for therapy in hypertension. Regulation of blood pressure – complex process RAAS ANP/BNP ADH Vasoconstriction: angiotensin II, vasopresin, epineprin (α1), serotonin, PGF/TXA2, endotelin, cofein, NPY sympatikus parasympatikus baroreflex compliance Vasodilatation: NO, adrenalin (β2), adenosin, acidosis, histamin, PGD2/PGE2/PGI2, prostacyclins, VIP, bradykinin Thomas M Coffman, Under pressure: the search for the essential mechanisms of hypertension , Nature Medicine 17, 1402–1409 (2011) let me remark that 400 years ago REGULATION IN CARDIOVASCULAR SYSTEM •Main function: • • keep relatively constantaneous arterial blood pressure •keep perfusion of tissues • Regulation of vessels tone •Tone of the vessels = basic tension of the smooth muscle inside of the wall • (vasoconstriction x vasodilatation) • •Regulation - local autoregulation • - system regulation Autoregulation •Autoregulation – the capacity of tissues to regulate their own blood flow •Myogenic theory – Bayliss phenomenon (as the pressure rises, the blood vessels are distended and the vascular smooth muscle fibres that surround the vessels contract; the wall tension is proportional to the distending pressure times the radius of the vessels – law of Laplace) • Autoregulation •Metabolic theory – vasodilator substances tend to accumulate in active tissue, and these metabolites also contribute to autoregulation •ending products of energetic metabolism – CO2, lactate acid, K+ •effect of hypoxia (circulation: vasodilatation x pulmonary circulation: vasoconstriction) •Adenosin – coronary circulation: vasodilatation • Autoregulation •by substances which releasing from: • endothelium • tissues • •Substances secreted by the ENDOTHELIUM •Vasodilatation: •Nitric oxide (NO) from endothelial cells •(originally called: EDRF) •Prostacyclin is produced by endothelial cells • • •Vazoconstriction: • Endothelins (polypeptids – 21peptides) • three isopeptides: ET 1, ET 2 , ET 3 •Substances secreted by the tissues: •Histamine – primarily tissue hormones. •General affect: vasodilatation - decrease periphery resistence, blood pressure • •KININS: 2 related vasodilated peptides •Bradykinin + lysylbradykinin (kallidin). •Sweat glands, salivary glands •10x strongers than histamine •Relaxation of smooth muscle, decrease blood pressure • Systemic regulation • •By hormones •Catecholamines – epinephrine, norepinephrine - effect as activation of sympathetic system •RAAS - stress situation •ADH - general vasoconstriction •Natriuretic hormones - vasodilatation Neural regulatory mechanism •Autonomic nervous system •Sympathetic: vasoconstriction •All blood vessels except capillaries and venules contain smooth muscle and receive motor nerve fibers from sympathetic division of ANS (noradrenergic fibers) -Regulation of tissue blood flow -Regulation of blood pressure •Parasympathetic part: vasodilatation •Only sacral parasympathetic cholinergic fibres (Ach) inervated arteriols from external sex organs • http://www.studentconsult.com/common/showimage.cfm?mediaISBN=0721632564&FigFile=S23283-015-f004.jpg &size=fullsize Sympathetic nervous system Fight or flight response Energy/store consumption Preganglionic neuron – Spinal cord -Thoraco - lumbar system Ganglia Paravertebral -Truncus sympathicus - Majority Prevertebral -Plexus aorticus Mostly diffuse effect Parasympathetic nervous system Rest and digest response Energy conservation/en. store production Preganglionic neuron – Brain stem and spinal cord – cranio-sacral system Ganglia Close to target organs or intramurally Mostly local effect http://www.studentconsult.com/common/showimage.cfm?mediaISBN=0721632564&FigFile=S23283-015-f004.jpg &size=fullsize Sympatthetic nervous system Fight or flight response Energy/store consumption Preganglionic neuron – Spinal cord -Thoraco - lumbar system Ganglia Paravertebral -Truncus sympathicus - Majority Prevertebral -Plexus aorticus Mostly diffuse effect Parasympathetic nervous system Rest and digest response Energy conservation/energy store production Preganglionic neuron – Brain stem and spinal cord – cranio-sacral system Ganglia Close to target organs or intramurally Mostly local effect http://ccn.aacnjournals.org/content/27/1/30/T1.large.jpg INTEGRATION of regulation in cardiovascular system •The regulation of the heart: •Rami cardiaci n. vagi •Cardiac decelerator center - medula oblongata (ncl.dorsalis, ncl. ambiguus) – parasympathetic fibres of nervus vagus • : vagal tone (tonic vagal discharge) • •Negative chronotropic effect (on heart rate) •Negative inotropic effect (on contractility) •Negative dromotropic effect (on conductive tissue) • INTEGRATION of regulation in cardiovascular system •The regulation of the heart: • nn. cardiaci •Cardiac accelerator center – spinal cord, sympathetic ganglia – sympathetic NS • •Positive chronotropic effect (on heart rate) •Positive inotropic effect (on contractility) •Positive dromotropic effect (on conductive tissue) • • INTEGRATION of regulation in cardiovascular system •Vasomotor centre (regulation for function of vessels) •Medula oblongata ü presoric area (rostral and lateral part –vasoconstriction – increase blood pressure ü üdepresoric area (medio-caudalis part – vasodilatation, decrease of blood pressure) • INTEGRATION of regulation in cardiovascular system • • •Influence by central nervous system • cerebral cortex • limbic cortex • hypothalamus Regulation of blood pressure Short - term regulation - baroreflex Middle - term regulation - humorals regulation • sympathetic - catecholamines • RAAS (decrease perfusion pressure in kidney – secretion of renin) • ADH Long – term regulation - kidney regulation arteries veins NTS X. IX. • •Baroreflex – in every day life •Orthostatic – clinostatic reaction •Valsalva maneuvre - defecation Laboratorní metody: Spontánní metody: § ve spektrální doméně - sekvenční analýza - vzájemná spektrální analýza § v časové doméně - a-index - neck suction - Valsalvův manévr - aplikace phenylephrinu změna délky tepového intervalu vyvolaná změnou systolického krevního tlaku o 1 mmHg A change of duration of pulse interval (in ms) due to a change of systolic blood pressure by 1 mmHg Laboratory methods: Spontaneous methods: § in frequency-domeain - Sequence analysis - cross-spectral analysis § in time-domain - a-index - neck suction - Valsalva manoever - Phenylephrin aplication E7C22FD0 Furlan R et al. Circulation 2003;108:717-723 msoDBE03 (#BP)$VR"$CO"$PP"$MAP BP-blood pressure, VR-venous return, CO-cardiac output, PP – pulse pressure, MAP-mean arterial pressure Records of circulatory parameters obr11 •Spectral analysis: •Carried out under standard conditions at various maneuvers (supine, standing); evaluated with 300 representative intervals RR / NN / •Another mathematical processing (Fourier transform) -length RR intervals are converted to cycles in Hz •The spectrum is divided into several components – low (LF: the sympathetic modulation) and high frequency (HF: vagal modulation) • People with reduced heart rate variability have a 5 times higher risk of death > > Parasympathetic NS Resetting of baroreflex •During repeated raising of blood pressure - e.g. in chronic hypertension - the force of baroreflex reaction on systemic blood pressure is lower •??? Why???mechanical changes in baroreceptors – decrease sensitivity due to structure changes on the vessels wall OR dysfunction of endotelium OR down-regulation in the brain center due to their increasing frequency of stimulation •Resseting of baroreflex can regulate the changes in blood pressures, but the resseting is unable to go back on „normal“ level •Resetting is a partially reversible – during a short-term influence of raising blood pressure • •Notice: in clinical practice: •!start treatment of hypertension in time! Middle – term regulation 1 catecholamines •Mediators of sympathetic nerves for baroreceptors and chemoreceptors •Sympathetic nervous system stimulates releasing of epinephrine and norepinephrine from adrenal medulla – main function: vasoconstriction – chronotropic effect – inotropic effect •Its function start during minutes or hours Middle – term regulation 2 Renin - angiotensin - aldosteron •System in kidney •+ •extrarenal system (in other tissues – brain, adrenal medulla, gonades, eyes) •+ •Intermediate system – heart, smooth muscles • •Renin – in juxtaglomerular cells in kidney •In liver – glycoprotein angiotensinogen – release angiotensin I (dekapeptid) – due to angiotensin converting ensyme to angiotensin II(oktapeptid) or angiotensin III (aminopeptidase) • •Angiotensin II – other way – chymase – in th heart and arterioles •(it is reason why during treatment by ACE blocatores – the angiotensin level is not reduce) Secretion of renin is modulated by •Sympathetic nervous system – beta 1 receptors activation – main mechanism of secretion of renin •Second way – by special mechanism due to sensitivity on sodium •exists a special intrarenal mechanism – negative sodium billance increase the renin secretion •???? hypothesis – macula densa register of sodium concentration in renal tubular system – this information transports to juxtaglomerular cells where activated renin-angiotensin system (has an influence on secretion of renin – release angiotensin II ); •Increse level of sodium – decrease releasing of renin (mediator – Nitric Oxide) •???Arterial pressure – stretch receptors (baroreceptory) in vas afferens (juxtaglomerular cells) – influence on blood pressure in kidney or also in systemic circulation??? Angiotensin II - Effects (Owerview) •Vasoconstriction •Change in renal hemodynamics – decrease of blood flow in kidney and glomerular filtration •Influence on reabsorption of sodium in renal tubules •It invokes or enhances the presynaptic release of noradrenaline •Stimulates the release of ADH • •Effect of ANGIOTENSIN III •Stimulation of aldosterone secretion from the adrenal cortex Middle – term regulation 3 ADH - vasopressin •During a strong decline of blood pressure • from posterior pituitary – vasoconstriction • •May be: slowly effect – retention of water in distal tubule and proximal part of collecting ducts Long – term regulation •Little is known about how this occurs • •Pressure diuresis regulates the volume in circulation and keep „pressure homeostasis“ •Blood pressure increases longer than 2 hours (persistant increase)– started pressure diuresis, its time duration a lot of days (increase blood pressure – increase excretion of sodium - osmotic activity – increase excretion of water ---decrease extravascular volume and decrease blood pressure) •a single control system which is not subject to adaptation – the action takes as long as the pressure is returned to the original values (or if its action is not reversed by other mechanisms) • With persistent decrease of BP - the opposite effect • • • Long – term system of pressure natriuresis •It is a cascade of regulatory processes: • the mechanical effect of increased blood flow through the kidney ... increased blood flow in the kidney papilla - increased renal interstitial hydrostatic pressure - increased tight junction of epithelial cells of the renal tubules for sodium - increased sodium excretion - increased excretion water - decrease in volume of circulatory fluids - pressure drop in the systemic circulation •System of internal renal baroreceptors ... pressure increase in vas afferens ... restriction of renin production - attenuation of renal sympathetic stimulation - decrease in sodium reabsorption, reduction of fluid volume - pressure drop •Na+- K+ - ATPase inhibitory factor – released from adrenal medulla (steroid-like digitalis - possibly ouabain) •Increased AT2 receptor expression for angiotensin II (may antagonize the effects of inadequate AT1 receptor stimulation, in rat experiments demonstrated - increased sodium and water excretion) •Others: bradykinin, urodilatin, renal natriuretic peptides Methodology of blood pressure measurement Misinterpretation of values C:\Documents and Settings\ja2\Dokumenty\DEMONSTRACE\krevní tlak u koně001.jpg Blood pressure measurement •The system pressure values are, for technical reasons, dependent on: •Measuring method used •Non-invasive methods: •auscultatory •oscillometry •ultrasound •photopletysmography •Invasive methods •indirect – Swan-Ganz´s catheter •direct – catheter with a pressure sensor at the end •Methodology •Clinical measurement – in ambulance - practitioner •Home measurement •24hour ambulatory blood pressure monitoring Austrian Von Basch „aneroid sfygmomanometr“ With baloon on wrist 1876 Italian physician Riva Rocci „mercury sfygmomanometr“ With cuff on the arm 1896 Palpatory method Auscultatory methods •based on detection of Korotkoff phenomenons •„gold standard“ •with comparison on intra-arterial measurement of blood pressure – we will find: lower values for SBP and higher values of DBP • /this is only technical systemic mistake – does not matter/ •According a guidelines for diagnostic of arterial hypertension: we diagnose arterial hypertension: repeated blood pressure increase above 140/90mmHg, demonstrated at least in two out of three measurements using the auscultation method in the clinical setting Auscultatory method Russian army surgeon Nikolaj Korotkoff 1904 „mercury sfygmomanometr“ The cuff on the arm, stethoscope in the area of the elbow Oscillometric method •Author: Mr. Marey – the first describe on 1876 •It has been repeatedly demonstrated that the oscillation of BP in the sphygmomanometric cuff is measured during its gradual discharge - the point of maximum oscillation corresponds to the mean arterial pressure measured invasively •Oscillations begin approximately around systolic pressure values and continue after deflation of the cuff = both systolic and diastolic pressure is estimated only indirectly based on empirical derived algorithms •Advantage: Less susceptible to external noise Disadvantage: definitely unreliability in physical activity - distortion by motion artifacts + susceptible to low-frequency mechanical vibrations Ultrasound method •The device includes an ultrasonic vibration generator and an ultrasonic sensor - placement via the brachial artery and under the sphygmomanometric cuff When deflate the cuff, it induces a systolic movement of the arterial wall that causes the Doppler phase shift in the transmitted ultrasound signal; diastolic BP is calculated by a significant reduction in arterial wall motions •Other variant: systolic BP based on blood flow detection - in newborns and small children Digital photoplethysmography •Continuously blood pressure measurement - „beat to beat“ – from digital artery • •Profesor Jan Peňáz – Department of Physiology – Masaryk university in Brno - patent 1969 • •Disadvantage: can not be used in conditions with peripheral vasoconstriction (shock states, vasoneurosis, diabetic angiopathy) 05 •We need than pressure in the cuff corresponded to the pressure of the digital artery •Method: photopletysmography •Recorded photoelectric plethysmogram •The new term: Transmural pressure – Pt (the pressure across the wall of the artery) •BP (blood pressure inside artery), Pc (pressure in cuff), Pt (transmural pressure) •We estimated: BP=Pc ….Pt=0 …..photoplethysmogram registered the highest amplitude of oscilation •Step by step increase of Pc, in the moment of the highest amplitude – feed-back loop started for obtained(keeping) the constant volume of the finger Penaz patent •He used the signal from the photocell to control the external cuff pressure and that to keep the finger volume unchanged. This has achieved that pressure in the cuff monitors blood pressure in the artery. Record of breathing and waves in circulatory parameters (Peňáz´s photoplethysmomanometr) obr11 Finapres (Ohmeda, USA) IMG_0869 P2290051 Invasive measurement of blood pressure •The most accurate measurement method of BP – BUT HIGH RISK: - difficult accessibility, risk of infection diseases Usage: BP monitoring in critical states (coronary units, intensive care units); in more complex therapeutic procedures •Indirect - Swan-Ganze catheter - hollow tube, on the vessel side with a hole, the other side connected to the sensor - filled with physiological solution - transfer of pressure changes from the vessel's light towards the sensor – inaccurate •Direct – special sensor – special microsensor on the vessel side - the blood pressure signal is transmitted from it • up-to-date catheters - signal transmission via fiber optics • Important for the diagnosis of all forms of pulmonary hypertension Methodology •Clinical statement •In keeping with a good practice is still auscultation method able to report reliable results • •We must rely on white-coat hypertension versus masked hypertension in some patients There is always higher BP in the case of BP measurement by physician and lower values measured by nurse or technician Methodology 2 •„Home“ blood presure measurement •Advantage: measurement by patients, elimination of white-coat hypertension effect, measurement in long period •Disadvantage: technical problem, correct measurement by patient •Classic oscillometry method – cuff on the arm •Attention on location of measurement on the wrist - in the vertical position - pressure above 15-20 mmHg higher than on the arm, even when in the heart position the SBP is higher by 2-3mmHg than on the arm •Finger position cuff (non digital photoplethysmography) - Higher values of 4 mmHg than on the arm (another characteristic of the pulse curve in the finger artery) •Values at home measurements are always lower than in the clinical setting – Hypertension society recommendation: BP higher than 135/85mmHg - are increased ! Methodology 3 •24 hour ambulatory blood pressure monitoring •Advantage: an overview of absolute values and variability in time-defined periods (! but still intermittent measurement!) •Oscillometric method •Information: SBP, DBP, pulse pressure, mean arterial pressure - profile of absolute values at monitored intervals; average and standard deviation for the period under review; % of the blood pressure parameters above the specified upper limit; calculation of different indexis; determination of variability of blood pressure fluctuation •The number of BP increases in more than 40% of all values in either on night – or day-time interval – dg: arterial hypertension • ABPM values are lower than clinical values - recommendations: • normal: below 135/85 daily and night under 120/70; 24 hour diameters 130/80 mmHg Methodology 4 •Continuously blood pressure measurement •Beat to beat record by Penaz method •BP is dynamic parameter • variability of fluctuation of heart rate and blood pressure – regulation by baroreflex – cooperation both parts of autonomic nervous system (symphathetic and parasymphathetic part) •Necessary component in clinical tests - head up table test (on inclined plane) and BP dysregulation in young subjects - dif.dg syncope •BP regulation research - maneuvers – Valsalva etc. ... .. •BP measurement in extreme situations: supersonic airplane pilots – overload condition, the cosmic program – weightlessness condition etc. Blood pressure in children C:\Documents and Settings\ja2\Dokumenty\LUHAČOVICE\grafy002.jpg Age influence on blood pressure in man and female Fölsch et al., Patologická fyziologie, Grada 2003 Classification BP values category Systolic BP Diastolic BP (mmHg) (mmHg) optimal < 120 < 80 normal 120 – 129 80 – 84 high normal pressure 130 – 139 85 – 89 Hypertension - mild 140 – 159 90 – 99 Hypertension - moderate 160 – 179 100 – 109 Hypertension - severe ≥ 180 ≥ 110 Izolated systolic hypertension ≥ 140 < 90 According the Guidelines of European Society of Cardiology 2013 C:\Documents and Settings\ja2\Dokumenty\LUHAČOVICE\grafy001.jpg •Current Hypertension Reports •October 2017, 19:84 | Cite as •Updated Guideline May Improve the Recognition and Diagnosis of Hypertension in Children and Adolescents; Review of the 2017 AAP Blood Pressure Clinical Practice Guideline •Janis M. Dionne • • For children aged 1 to 13 years/aged ≥13 years •Normal BP: <90th percentile // <120/ <80 mmHg •Elevated BP: ≥ 90th percentile to <95th percentile//120/ <80 to 129/ <80 mmHg •or 120/80 mmHg to <95th percentile (whichever is lower) •Stage 1 HTN: : ≥ 95th percentile to <95th percentile+12 mmHg//130/80 to 139/89 mmHg •Or 130/80 to 139/89 mmHg (whichever is lower) •Stage 2 HTN: ≥ 95th percentile +12 mmHg// ≥140/90 mmHg •Or ≥140/90 mmHg (whichever is lower) •Flynn JT, Kaelber DC, Baker-Smith CM, Blowey D, Carroll AE, Daniels SR, et al., for the Subcommittee on Screening and Management of High Blood Pressure in Children. Clinical practice guideline for screening and management of high blood pressure in children and adolescents. Pediatrics. 2017;140(3):e20171904. https://doi.org/10.1542/peds.2017-1904. https://static-content.springer.com/image/art%3A10.1007%2Fs11906-017-0780-8/MediaObjects/11906_2017 _780_Tab3d_HTML.gif https://static-content.springer.com/image/art%3A10.1007%2Fs11906-017-0780-8/MediaObjects/11906_2017 _780_Tab3c_HTML.gif https://static-content.springer.com/image/art%3A10.1007%2Fs11906-017-0780-8/MediaObjects/11906_2017 _780_Tab3a_HTML.gif https://static-content.springer.com/image/art%3A10.1007%2Fs11906-017-0780-8/MediaObjects/11906_2017 _780_Tab3b_HTML.gif Blood pressure •Immediately after birth – high blood pressure: •Stress after delivery, increase concentration of catecholamine and cortizol •After 1st day …….. 70/50 mmHg: •Open of pulmonary and intestine circulation •During pubertas: •Development of regulatory mechanism •Stimulation of external world •Newborn 80/46 mmHg 10.6/6.1 kPa •3 years 100/67 13.3/8.9 •10-11 years 111/58 14.8/7.7 •13-14 years 118/60 15.7/8.0 Blood presure measurement in newborn and children •Korotkoff method – for children over 1 year – use a correct size of cuff • •In the newborns, auscultation phenomena are poorly audible - there may be an underestimation of SBP • •better use the ultrasound method of the blood flow detector •The size of cuff • •Body weight age size of cuff •1 500 g newborn 2.5 cm • 5 kg 3 month 4.5 cm •10 kg 15 month 6 cm •30 kg 9 year 7.5 cm •more than • 30 kg 10 and more years 12 cm Specific features measurement • Pregnant women •Physiological profile of pregnancy - decrease of BP with increase in cardiac output and large decrease of peripheral resistance = special hyperkinetic conditions - Korotkoff phenomena we auscultated even after deflation of the cuff - diastolic BP we estimated in IV phase of Korotkoff phenomena • •Elderly people with atherosclerosis - poor compressibility of the artery wall by a compression cuff - we need to inflate more - so we measure falsely higher SBP values - pseudohypertension • •Obese persons – using the right size of the cuff !!!!! using a standard cuff – overstocking of SBP •Dynamic physical exercise - auscultation method may underestimate SBP by 15 mmHg, during recovery phase - overstatement of up to 30mmHg SBP; DBP less frequently but falsely low - better use for DBP measurement reading from phase IV of Korotkoff sounds Actual blood pressure values are dependent on: •factors that are conditioned by the organism •on the measurement method • •in which conditions the measurements are performed (methodology) • •even on accuracy and reliability of instruments (technical page - necessary tests and calibration of pressure device / 1 year) • •THIS MUST BE ALLOWED TO CONSIDER AT THE MEASUREMENT IN CLINICAL PRACTICE THANK YOU FOR YOUR ATTENTION