Understanding the Haemodynamics of Hypertension
- 32 Downloads
Purpose of review
This article introduces the haemodynamic principles that underpin the pathophysiology of hypertension and introduces a rational physiological approach to appropriate pharmacologic treatment.
Outdated understanding of haemodynamics based on previous measurement systems can no longer be applied to our understanding of the circulation. We question the current view of hypertension as defined by a predominantly systolic blood pressure and introduce the concept of vasogenic, cardiogenic and mixed-origin hypertension. We postulate that failure to identify the individual’s haemodynamic pattern may lead to the use of inappropriate medication, which in turn may be a major factor in patient non-compliance with therapeutic strategies. A population-based approach to treatment of hypertension may lead to suboptimal functional dynamics in the individual patient. Finally, we question the validity of current guidelines and published evidence relating morbidity and mortality to the future treatment of hypertension.
The importance of individual haemodynamic profiles may be pivotal in the understanding, diagnosis and treatment of hypertension if optimal control with minimal adverse effects is to be achieved. Research based on individual haemodynamic patterns is overdue.
KeywordsBlood pressure Cardiac output Compliance Haemodynamics Hypertension Pathophysiology Vascular resistance
Compliance with Ethical Standards
Conflict of Interest
The authors declare no conflicts of interest. Specifically, neither of the authors has any financial interest in any company or organisation, nor has received any financial benefit or inducement related to the subject matter of this review article.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by any of the authors.
Papers of particular interest, published recently, have been highlighted as: •• Of major importance
- 1.•• Phillips RA, Smith BE, Madigan VM. Stroke volume monitoring: novel continuous wave doppler parameters, algorithms and advanced noninvasive haemodynamic concepts. Curr Anesthesiol Rep. 2017;7(4):387–98. https://doi.org/10.1007/s40140-017-0235-4. This review summarises the methods available to the clinician to evaluate haemodynamics using non- and minimally-invasive methods. It includes the basic science of Doppler methods and echocardiography, along with the strengths and limitations of each method. CrossRefPubMedPubMedCentralGoogle Scholar
- 2.Lin ACW, Lowe A, Sidhu K, Harrison W, Ruygrok P, Stewart R. Evaluation of a novel sphygmomanometer, which estimates central aortic blood pressure from analysis of brachial artery suprasystolic pressure waves. J Hypertens. 2012;30(9):1743–50. https://doi.org/10.1097/HJH.0b013e3283567b94.CrossRefPubMedGoogle Scholar
- 4.•• Hall JB. Searching for evidence to support pulmonary artery catheter use in critically ill patients. JAMA. 2005;294(13):1693–4. Although a little dated, this editorial from 2005, some 35 years after the introduction of the pulmonary artery catheter (PAC), discusses the evidence in terms of patient outcomes and the impact, or more accurately, lack of impact, of the PAC. Although often considered or referred to as the “gold standard” of haemodynamic monitoring and cardiac output measurement, in fact there is little evidence to support this view. The ESCAPE trial which was terminated early due to excessive adverse effects in the PAC group is also discussed, as is the case for using non-PAC methods of evaluating haemodynamics. CrossRefPubMedGoogle Scholar
- 6.Phillips RA, Hood SG, Jacobson BM, West MJ, Wan L, May CN. Pulmonary artery catheter (PAC) accuracy and efficacy compared with flow probe and transcutaneous Doppler (USCOM): an ovine cardiac output validation. Critical Care Research and Practice, vol. 2012, Article ID 621496, 9 pages, 2012. https://doi.org/10.1155/2012/621496
- 7.•• Sramek BB. Haemodynamic management. http://www.hemodynamicsociety.org/hemodynamicmanagement.html#Per-beat_Hemodynamics. This on-line paper is a good primer in basic haemodynamics and cardiovascular physiology. The haemodynamic neophyte should read this relatively brief introduction to the science before proceeding to the more complex matters dealt with later in this review.
- 8.•• Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol. 2017; https://doi.org/10.1016/j.jacc.2017.11.006. A heavy document but an excellent source of information and evidence underpinning the current thinking regarding the treatment of hypertension. Remarkably, the document does not contain any of the following phrases: hemodynamics, cardiac output, cardiac index, stroke volume, vascular resistance or vascular impedance. The same is also true of reference 9.
- 9.2013 Practice guidelines for the management of arterial hypertension of the European Society of Hypertension (ESH) and the European Society of Cardiology (ESC): ESH/ESC Task Force for the Management of Arterial Hypertension. ESH/ESC Task Force for the Management of Arterial Hypertension. J Hypertens. 2013;31(10):1925–38. https://doi.org/10.1097/HJH.0b013e328364ca4c.CrossRefGoogle Scholar
- 15.Smith BE. Rapid non-invasive determination of ventricular preload. Anaesth Intensive Care. 2008;36(4):609.Google Scholar
- 25.Hannah J, Hillier M. Applied mechanics. 3rd ed. United Kingdom: Pearson; 1995. p. 180–210.Google Scholar
- 26.O’Malley J. Schaum’s outline of basic circuit analysis. 2nd ed. New York: McGraw-Hill; 2011. p. 232–8.Google Scholar
- 34.Krzesiński P, Gielerak G, Stańczyk A, Piotrowicz K, Skrobowski A. Who benefits more from hemodynamically guided hypotensive therapy? The experience from two randomized, prospective and controlled trials. Ther Adv Cardiovasc Dis. 2016;10(1):21–9. https://doi.org/10.1177/1753944715618593.CrossRefPubMedGoogle Scholar
- 35.•• Taler SJ. Individualizing antihypertensive combination therapies: clinical and hemodynamic considerations. Curr Hypertens Rep. 2014;16(7):451. https://doi.org/10.1007/s11906-014-0451-y. A relatively short review of the evidence, but the article is long on common sense and evidence-based approaches to investigation, diagnosis and treatment of hypertension. Professor Taler concludes that current guidelines offer limited guidance beyond selection of the first and possibly second treatment agents. Meanwhile, haemodynamic measurements can be obtained efficiently, non-invasively and serially. CrossRefPubMedPubMedCentralGoogle Scholar
- 41.•• Hatle L, Angelsen B. Doppler ultrasound in cardiology. Physical principles and applications. Philadelphia: Lea and Febiger; 1982. p. 192. A seminal work that should be compulsory reading for anybody intending to use echocardiography or Doppler techniques to measure volume flows in the heart. The scientific basis of the methods and more importantly, the limitations and pitfalls of the techniques are well explained and are both enlightening and sobering. This should be viewed along with reference 42 for a more complete understanding of the issues involved in using echocardiographic techniques at the point of care. Google Scholar
- 43.Kusumoto F, Venet T, Schiller NB, Sebastian A, Foster E. Measurement of aortic blood flow by Doppler echocardiography: temporal, technician, and reader variability in normal subjects and the application of generalizability theory in clinical research. J Am Soc Echocardiog. 1995;8(5Pt1):647–53.CrossRefGoogle Scholar
- 46.Cattermole GN, Leung PY, Ho GY, Lau PW, Chan CP, Chan SS, Smith BE, Graham CA, Rainer TH. The normal ranges of cardiovascular parameters measured using the ultrasonic cardiac output monitor. Physiol Rep. 2017;5(6). https://doi.org/10.14814/phy2.13195.
- 49.Kupersztych-Hagege E, Teboul JL, Artigas A, Talbot A, Sabatier C, Richard C, et al. Bioreactance is not reliable for estimating cardiac output and the effects of passive leg raising in critically ill patients. Brit J Anaesth. 2013;111(6):961–6. https://doi.org/10.1093/bja/aet282.CrossRefPubMedGoogle Scholar
- 50.Magliocca A, Rezoagli E, Anderson TA, Burns SM, Ichinose F, Chitilian HV. Cardiac output measurements based on the pulse wave transit time and thoracic impedance exhibit limited agreement with thermodilution method during orthotopic liver transplantation. Anesth Analg. 2017; https://doi.org/10.1213/ANE.0000000000002171.
- 52.Maass SW, Roekaerts PM, Lancé MD. Cardiac output measurement by bioempedance and noninvasive pulse contour analysis compared with the continuous pulmonary artery thermodilution technique. J Cardiothorac Vasc Anesth. 2014;28(3):534–9. https://doi.org/10.1053/j.jvca.2014.01.007.CrossRefPubMedGoogle Scholar
- 53.Bogui P, Balayssac-Siransy E, Connes P, Tuo N, Ouattara S, Pichon A, et al. The PhysioFlow thoracic impedance meter is not valid for the measurements of cardiac hemodynamic parameters in chronic anemic patients. PLoS One. 2013;8(10):e79086. https://doi.org/10.1371/journal.pone.0079086.CrossRefPubMedPubMedCentralGoogle Scholar
- 54.Taylor K, Manlhiot C, McCrindle B, Grosse-Wortmann L, Holtby H. Poor accuracy of noninvasive cardiac output monitoring using bioimpedance cardiography [PhysioFlow(R)] compared to magnetic resonance imaging in pediatric patients. Anesth Analg. 2012;114(4):771–5. https://doi.org/10.1213/ANE.0b013e318246c32c.CrossRefPubMedGoogle Scholar
- 55.Taylor K, La Rotta G, McCrindle BW, Manlhiot C, Redington A, Holtby H. A comparison of cardiac output by thoracic impedance and direct Fick in children with congenital heart disease undergoing diagnostic cardiac catheterization. J Cardiothorac Vasc Anesth. 2011;25(5):776–9. https://doi.org/10.1053/j.jvca.2011.05.002.CrossRefPubMedGoogle Scholar
- 56.Sharma V, Singh A, Kansara B, Karlekar A. Comparison of transthoracic electrical bioempedance cardiac output measurement with thermodilution method in post coronary artery bypass graft patients. Ann Card Anaesth. 2011;14(2):104–10. https://doi.org/10.4103/0971-9784.81564.CrossRefPubMedGoogle Scholar
- 57.Rodríguez-Artalejo F, Guallar E, Borghi C, Dallongeville J, De Backer G, Halcox JP, et al. Rationale and methods of the European Study on Cardiovascular Risk Prevention and Management in Daily Practice (EURIKA). BMC Public Health. 2010;10:382. https://doi.org/10.1186/1471-2458-10-382.CrossRefPubMedPubMedCentralGoogle Scholar
- 58.Palafox B, Goryakin Y, Stuckler D, et al. Does greater individual social capital improve the management of hypertension? Cross-national analysis of 61,229 individuals in 21 countries. BMJ Glob Health. 2017;2(4):e000443. https://doi.org/10.1136/bmjgh-2017-000443.eCollection2017.
- 59.Attaei MW, Khatib R, McKee M, PURE study investigators, et al. Availability and affordability of blood pressure-lowering medicines and the effect on blood pressure control in high-income, middle-income, and low-income countries: an analysis of the PURE study data. Lancet Public Health. 2017;2(9):e411–9. https://doi.org/10.1016/S2468-2667(17)30141-X.CrossRefPubMedGoogle Scholar
- 61.Tamblyn R, Winslade N, Qian CJ, Moraga T, Huang A. What is in your wallet? A cluster randomized trial of the effects of showing comparative patient out-of-pocket costs on primary care prescribing for uncomplicated hypertension. Implement Sci. 2018;13(1):7. https://doi.org/10.1186/s13012-017-0701-x.CrossRefPubMedPubMedCentralGoogle Scholar
- 66.McEniery CM, Yasmin MDB, Munnery M, Wallace SM, Rowe CV, Cockcroft JR, et al. Central pressure: variability and impact of cardiovascular risk factors. The Anglo-Cardiff Collaborative Trial II. Hypertension. 2008;51:1476–82. https://doi.org/10.1161/HYPERTENSIONAHA.107.105445.CrossRefPubMedGoogle Scholar