Assessment of afterload

  • Nikolai Kolev
  • Günter Huemer
  • Michael Zimpfer


Afterload can be thought of as the tension acting on the fibers in the ventricular wall during ejection or as the impedance to ejection.1 Although it is influenced importantly by the arterial pressure, it is not synonymous with peripheral arterial pressure, peripheral vascular tone, or systemic vascular resistance. Afterload is best defined as left ventricular wall stress during ejection according to La Place’s law:2
$${\text{Wall stress = PR/2h,}}$$
where P is the intracavitary pressure, R is the radius of curvature, and h is the wall thickness. Thus, wall stress is directly related to chamber dimension, and inversely related to wall thickness. While arterial pressure is related to the product cardiac output and systemic vascular resistance, afterload (wall stress) is a function of ventricular size and arterial pressure. Fig. 5.1. illustrates the great difference between wall stress, i.e., afterload, and systolic ventricular pressure.


Systemic Vascular Resistance Wall Stress Left Ventricular Pressure Peak Systolic Pressure Central Aortic Pressure 
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  1. 1.
    Braunwald E, Sonnenblick EH, Ross J Jr. Mechanisms of cardiac contraction and relaxation. In: Braunwald E, ed, Heart disease. 4th ed. WB Saunders, Philadelphia, pp 351–418, 1992Google Scholar
  2. 2.
    Goertz AW, Lindner KH, Seefeld C, Schirmer U, Beyer M, Georgieff M. Effect of phenylephrine bolus administration on global left ventricular function in patients with coronary artery disease and patients with valvular aortic stenosis. Anesthesiology 78: 834–841, 1993PubMedCrossRefGoogle Scholar
  3. 3.
    Kaplan J A. Cardiac Anesthesia. 3rd ed. Grune and Stratton, New York, London, pp 1178, 1991Google Scholar
  4. 4.
    Kikura M, Shanewise JS, Levy JH. Intraoperative assessment of myocardial function. Curr Opin Anesth 4: 42–52, 1993Google Scholar
  5. 5.
    Grossman W, Jones D, McLaurin LP. Wall stress and patterns of hypertrophy in the human left ventricle. J Clin Invest 56: 56–64, 1975PubMedCrossRefGoogle Scholar
  6. 6.
    Lang LM, Briller RA, Neumann A, Borow KM. Assessment of afterload. In: Kreber RE, ed, Echocardiography in coronary artery disease. Future, Mount Kiosk, pp 224–225, 1988Google Scholar
  7. 7.
    Quinones MA, Mokotoff DM, Nouri S, Winters WL, Miller RR. Noninvasive quantifi-cation of left ventricular wall stress. Validation of the method and application to assessment of chronic pressure overload. Am J Cardiol 45: 782–790, 1980PubMedCrossRefGoogle Scholar
  8. 8.
    Huemer G, Kolev N, Kurz A, Zimpfer M. Influence of positive end-expiratory pressure on right and left ventricular performance assessed by Doppler two-dimensional echocardiography. Chest 106: 67–73, 1994PubMedCrossRefGoogle Scholar
  9. 9.
    Golan SD, Borow KM, Neumann A. Effects of loading conditions and contractile state (methoxamine and dobutamine) on left ventricular early diastolic function in normal subjects. Am J Cardiol 55: 790–796, 1985CrossRefGoogle Scholar
  10. 10.
    Reichek N, Wilson J, St J Sutton M, Plappert TA, Goldberg S, Hirshfeld JW. Noninvasive determination of left ventricular end-systolic stress: validation of the method and initial application. Circulation 65: 99–108, 1982PubMedCrossRefGoogle Scholar
  11. 11.
    Kikura M, Ikeda T, Kazman T, Ikeda K. Effect of prostaglandin Ej on myocardial contractility in dogs anesthetized with halothane: Load-independent and noninvasive assessment using transesophageal echocardiography. J Cardiothorac Vase Anesth 6: 586–592, 1992CrossRefGoogle Scholar
  12. 12.
    Kikura M, Ikeda K. Comparison of effects of sevoflurane-nitrous oxide and enflurane- nitrous oxide on myocardial contractility in humans: load-independent and noninvasive assessment with transesophageal echocardiography. Anesthesiology 79: 235–243, 1993PubMedCrossRefGoogle Scholar
  13. 13.
    Douglas PS. Comparison of echocardiographic methods for measurement of left ventricular shortening and wall stress. J Am Coll Cardiol 9: 945–949, 1987PubMedCrossRefGoogle Scholar
  14. 14.
    Smith JS, Benefiel DJ, Beaupre PN, Sohn YJ, Lurz FW, Bird B, Bouchard A, Schiller NB, Cahalan MC, Roizen MF. Effects of phenylephrine on myocardial performance during carotid endarterectomy (Abstr). Anesthesiology 61: A56, 1984CrossRefGoogle Scholar
  15. 15.
    O’Kelly BF, Tubau JF, Knight AA, London MJ, Verrier ED, Mangano DT. Measurement of left ventricular contractility using transesophageal echocardiography in patients undergoing coronary artery bypass grafting. Am Heart J 122: 1041–1048, 1991PubMedCrossRefGoogle Scholar
  16. 16.
    Cunningham AJ, Turner J, Grosso L, Rosenbaum S, Rafferty T. Transesophageal assessment of hemodynamic function during laparoscopic cholecystectomy (Abstr). Anesth Analg 76: S64, 1993CrossRefGoogle Scholar
  17. 17.
    Colan SD, Borow KM, Neumann A. The left ventricular end-systolic wall stress- velocity of the fiber shortening relation: A load independent index of myocardial contractility. J Am Coll Cardiol 4: 715–719, 1984PubMedCrossRefGoogle Scholar
  18. 18.
    Colan SD, Borow KM, Neumann A. Use of the calibrated pulse tracing for calculation of left ventricular pressure and wall stress throughout ejection. Am Heart J 109: 1306–1310, 1985PubMedCrossRefGoogle Scholar
  19. 19.
    Janz RF. Estimation of local myocardial stress. Am J Physiol 242: H875, 1982PubMedGoogle Scholar
  20. 20.
    Kolev N, Huemer G, Ihra G, Spiss CS, Zimpfer M. Assessment of afterload in case of regional systolic abnormalities. Int J Anaesth (in press), 1995Google Scholar

Copyright information

© Springer-Verlag/Wien 1995

Authors and Affiliations

  • Nikolai Kolev
    • 1
  • Günter Huemer
    • 1
  • Michael Zimpfer
    • 2
  1. 1.Department of Anesthesiology and General Intensive CareUniversity of ViennaAustria
  2. 2.University of ViennaAustria

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