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A New Method of Analyzing Regional Myocardial Function of the Ventricle

  • Motoaki Sugawara
  • Kiyoharu Nakano

Summary

We introduce a new method of defining regional work and regional elastic modulus of the myocardium of the ventricular wall using the relationship between mean wall stress (σ) and the natural logarithm of reciprocal of wall thickness (ln(1/H)). The area surrounded by the loop described by the σ-ln (1/H) relationship during a cardiac cycle-is equal to regional work per unit volume of myocardium per stroke. The slope of the σ-ln (1/H) relationship corresponds to Young’s modulus of an incompressible Hookean material. The end-systolic σ-ln(1/H) data point moves on a rectilinear line during pre-and afterloadings. The slope of this line is not affected by alterations in pre-and afterloads, but changes singnificantly due to the changes in the contractile state. Therefore, the slope can be regarded as the normalized Emax, i.e., a normalized index of myocardial contractility index of myocardial contractility.

Keywords

Ventricular Wall Wall Stress Aortic Constriction Wall Tension Contractile State 
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References

  1. 1.
    Huisman RM, Sipkema P, Westerhof N, Elzinga G (1980) Comparison of models used to calculate left ventricular wall force. Med Biol Eng Comput 18: 133–144PubMedCrossRefGoogle Scholar
  2. 2.
    Yin FCP (1981) Ventricular wall stress. Circ Res 49: 829–842PubMedGoogle Scholar
  3. 3.
    Sugawara M, Tamiya K, Nakano K (1985) Regional work of the ventricle:Wall tension-area relation. Heart Vessels 1: 133–144PubMedCrossRefGoogle Scholar
  4. 4.
    Goto Y, Suga H, Yamada O, Igarashi Y, Saito M, Hiramori K (1986) Left ventricular regional work from wall tension-area loop in canine heart. Am J Physiol (Heart Circ Physiol) 250(19): H151-H158PubMedGoogle Scholar
  5. 5.
    Goto Y, Igarashi Y, Yamada O, Hiramori K, Suga H (1988) Hyperkinesis without the Frank-Starling mechanism in a nonischemic region of acutely ischemic excised canine heart. Circulation 77: 468–477PubMedCrossRefGoogle Scholar
  6. 6.
    Goto Y, Igarashi Y, Yasumura Y, Nozawa T, Futaki S, Hiramori K, Suga H (1988) Integrated regional work equals total left ventricular work in regionally ischemic canine heart. Am J Physiol (Heart Circ Physiol) 254(23): H894–H904Google Scholar
  7. 7.
    Nakano K, Sugawara M, Tamiya K, Satomi G, Koyanagi H (1986) A new approach to defining regional work of the ventricle and evaluating regional cardiac function: Mean wall stress-natural logarithm of reciprocal of wall thickness relationship. Heart Vessels 2: 74–80PubMedCrossRefGoogle Scholar
  8. 8.
    Sugawara M, Nakano K (1987) A method of analyzing regional myocardial function: Mean wall stress-area strain relationship. Jpn Circ J 51: 120–124PubMedCrossRefGoogle Scholar
  9. 9.
    Nakano K, Sugawara M, Kato T, Sasayama S, Carabello BA, Asanoi H, Umemura J, Koyanagi H (1988) Regional work of the human left ventricle calculated by wall stress and the natural logarithm of reciprocal of wall thickness. J Am Coll Cardiol 12: 1442–1448PubMedCrossRefGoogle Scholar
  10. 10.
    Suga H, Sagawa K (1974) Instantaneous pressure-volume relationships and their ratio in excised, supported canine left ventricle. Circ Res 35: 117–126PubMedGoogle Scholar
  11. 11.
    Sagawa K (1981) The end-systolic pressure-volume relation of the ventricle: Definition, modifications and clinical use. Circulation 63: 1223–1227PubMedCrossRefGoogle Scholar
  12. 12.
    Suga H, Yamada O, Goto Y, Igarashi Y, Yasumura Y, Nozawa T (1986) Reconsideration of normalization of Emax for heart size. Heart Vessels 2: 67–73PubMedCrossRefGoogle Scholar
  13. 13.
    Sommerfeld A (1964) Mechanics of deformable bodies, (translated by Kuerti G) Academic Press, New York, pp 65–66Google Scholar

Copyright information

© Springer-Verlag Tokyo 1989

Authors and Affiliations

  • Motoaki Sugawara
  • Kiyoharu Nakano
    • 1
  1. 1.Tokyo Women’s Medical CollegeThe Heart Institute of JapanTokyoJapan

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