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Basic Research in Cardiology

, Volume 78, Issue 4, pp 384–395 | Cite as

Application of an end-systolic pressure-segment length relationship for measuring regional contractility

  • A. J. Liedtke
  • St. H. Nellis
  • C. W. Fultz
  • M. Dietz
  • L. F. Whitesell
Original Contributions

Summary

A method for estimating regional contractility is described using the end-systolic relationships between left ventricular pressure and myocardial segment-lengths in rapidly volume-loaded beats. The approach was based on the success of previously developed end-systolic relationships between left ventricular used to describe glopal contractility in beating hearts. The regional end-systolic relationship was more complicated than its global counterpart, which was load independent, and appeared curvilinear to rapid volume loading. As an approximation of this relationship, a linear slope was constructed between maximum and minimum (pre-ejection) loaded beats of equal cycle length. Because of its load dependency and in order to compare slope relationships between interventions, slope functions were derived only from similarly loaded beats either within or between interventions. Slopes generated by this technique had a reasonable constancy at control conditions and coronary flows with an average SEM of 9.1% of the slope means. End-systolic slopes also appeared sensitive to changes in contractile state, increasing appropriately following treatments with dobutamine and decreasing after propranolol. Following shifts in the end-systolic slopes were unreliable, however, in describing the regional changes in contractility with ischemia. At milder levels of flow restriction, the slopes declined as expected. At moderate levels of flow restriction, the pressure-segment loops shifted markedly rightward and the slope increased. At advanced levels of ischemia, the loops were so distorted, that end-systole could not be identified accurately and the loops essentially described the diastolic compliance characteristics of the left ventricle.

Thus the slope estimates of regional contractility as described in this report provided a reliable assessment of inotropic background during modifications with positive and negative inotropic drugs but became invalid as systolic shortening was replaced by aneurysmal bulging high-grade ischemia.

Key words

positive and negative inotropy dobutamine propranolol regional ischemia working swine hearts 

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References

  1. 1.
    Grossman, W., B. Braunwald, T. Mann, L. P. McLauren, L. H. Green: Contractile state of the left ventricle in man as evaluated from end-systolic pressure-volume relations. Circulation56, 845–852 (1977).PubMedGoogle Scholar
  2. 2.
    Hatch, R. C., R. W. Hughes, and H. Bozivich: Effect of resting blood pressure on pressure responses to drugs in carotid occlusion. Amer. J. Physiol.213, 1515–1519 (1967).PubMedGoogle Scholar
  3. 3.
    Liedtke, A. J., S. H. Nellis: The effects of buffered pyruvate on regional cardiac function in moderate, short-term ischemia. Circulat. Res.43, 189–199 (1978).PubMedGoogle Scholar
  4. 4.
    Maughan, W. L., K. Sunagawa, K. Sagawa: Rightward shift of the canine left ventricular end-systolic pressure-volume relation with regional ischemia. Circulation64 IV-230 (1981).Google Scholar
  5. 5.
    Nivatpumin, T., S. Katz, J. Scheuer: Peak left ventricular systolic pressure/end-systolic volume ratio: A sensitive detector of left ventricular disease. Amer. J. Cardiol.43, 969–977 (1979).PubMedGoogle Scholar
  6. 6.
    Noble, M. I. M.: Problems concerning the application of concepts of muscle mechanics to the determination of the contractile state of the heart. Circulation45, 252–255 (1972).PubMedGoogle Scholar
  7. 7.
    Osbakken, M., A. A. Bove, J. F. Spann: Left ventricular function in chronic aortic regurgitation with reference to end-systolic pressure, volume and stress relations. Amer. J. Cardiol.47, 193–198 (1981).PubMedGoogle Scholar
  8. 8.
    Pagani, M., S. F. Vatner, H. Baig, B. Braunwald: Initial myocardial adjustments to brief periods of ischemia and repurfusion in the conscious dog. Circulat. Res.43, 83–92 (1978).PubMedGoogle Scholar
  9. 9.
    Parmley, W. W., L. Chuck, E. H. Sonnenblick: Relation of Vmax to different models of cardiac muscle. Circulat. Res.30, 34–43 (1972).PubMedGoogle Scholar
  10. 10.
    Piene, H., J. W. Covell: A force-length-time relationship describes the mechanics of canine left ventricular wall segments during aurotonic contractions. Circulat. Res.49, 70–79 (1981).PubMedGoogle Scholar
  11. 11.
    Sagawa, K.: The end-systolic pressure-volume relation of the ventricle: definition, modifications and clinical use. Circulation63, 1223–1227 (1981).PubMedGoogle Scholar
  12. 12.
    Schuler, G., K. von Olshausen, F. Schwarz, H. Mehmel, H. Mehmel, M. Hofman, H. J. Hermann, D. Lange, W. Kubler: Noninvasive assessment of myocardial contractility in asymptomatic patients with severe aortic regurgitation and normal left ventricular ejection fraction at rest. Amer. J. Cardiol.50, 45–52 (1982).PubMedGoogle Scholar
  13. 13.
    Suga, H., K. Sagawa: Instantaneous pressure-volume relationships and the ratio in the excised, supported canine left ventricle. Circulat. Res.35, 117–126 (1974).PubMedGoogle Scholar
  14. 14.
    Tyberg, J. V., J. S. Forrester, H. L. Wyatt, S. J. Goldner, W. W. Parmley, H. J. C. Swan: An analysis of segmental ischemic dysfunction utilizing the pressurelength loops. Circulation49, 748–754 (1974).PubMedGoogle Scholar
  15. 15.
    Urschel, C. W., P. S. Vokonas, A. H. Henderson, A. J. Liedtke, L. D. Horwitz, E. H. Sonnenblick: Critical evaluation of indices of myocardial contractility derived from the isovolumic phase of contraction. Cardiol.65, 4–22 (1980).Google Scholar
  16. 16.
    Weber, K. T., J. S. Janicki: Instantaneous force-velocity-length relations in isolated canine heart. Amer. J. Physiol.232, H241-H249 (1977).PubMedGoogle Scholar

Copyright information

© Dr. Dietrich Steinkopff Verlag 1983

Authors and Affiliations

  • A. J. Liedtke
    • 1
  • St. H. Nellis
    • 1
  • C. W. Fultz
    • 1
  • M. Dietz
    • 1
  • L. F. Whitesell
    • 1
  1. 1.Division of CardiologyThe Pennsylvania State University, The Milton S. Hershey Medical CenterHershey

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