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Cardiovascular Engineering

, Volume 7, Issue 1, pp 32–38 | Cite as

Novel Means to Monitor Cardiac Performance: The Impact of the Force-frequency and Force-interval Relationships on Recirculation Fraction and Potentiation Ratio

  • Sarah E. Ahlberg
  • Robert C. Hamlen
  • Daniel L. Ewert
  • Paul A. Iaizzo
  • Lawrence J. Mulligan
Original Paper

Abstract

Insights into intracellular calcium regulation and contractile state can be accomplished by changing pacing rate. Steady-state increases in heart rate (HR) (force-frequency relationship, FFR), and introduction of extrasystoles (ES) (force-interval relationship, FIR) have been used to investigate this relationship. This study focused on the recirculation fraction (RF) and potentiation ratio (PR), obtained from the recovery of the FFR and FIR. These parameters may provide insight on intracellular Ca2+ regulation. Left ventricular (LV) pressures and HR were assessed in anesthetized canines (n = 7). Intrinsic data were collected prior to and following HR increases to 150, 180, and 200 bpm, as well as following delivery of an ES at 280 ms. The RF was calculated as the slope of dP/dtmax(n + 1) vs. dP/dtmax(n), where n = beat number. The PR was calculated by normalizing dP/dtmax from the first beat following the ES (or the last paced beat) to the steady-state dP/dtmax. The RF due to an ES was not significantly different than that from a HR of 200 bpm. The PR from an ES was not significantly different than from a HR of 150 bpm. The impact of an ES delivered at an interval of 280 ms produces a PR similar to that from a HR of 150 bpm; yet, it recovers similarly to the termination of pacing at 200 bpm, eliciting a similar RF value. The method of measuring RF by an ES versus an increased HR may provide a safer and more feasible approach to collecting diagnostic information.

Keywords

Intracellular Ca2+ handling Pacing Contractile function Heart failure Diagnostics 

Notes

Acknowledgments

Much gratitude is owed to Monica Mahre for her assistance in the editing of this manuscript. Financial support was provided by Medtronic, Inc. and Biomedical Engineering Institute, University of Minnesota.

References

  1. Bhargava V, Shabetai R, Mathiasen R, Dalton N, Hunter J, Ross J. Loss of adrenergic control of the force-frequency relation in heart failure secondary to idiopathic or ischemic cardiomyopathy. Am J Cardiol 1998;81:1130–7PubMedCrossRefGoogle Scholar
  2. Burkhoff D, Hunter W. Applicability of myocardial interval-force relationships to the whole ventricle: studies in isolated perfused hearts. In: Noble M, Seed W, editors. The interval-force relationship of the heart: Bowditch revisited. Cambridge: Cambridge University Press; 1992. p. 283–300Google Scholar
  3. Cooper I, Noble M. A model for interval-force phenomena: unresolved issues. In: Noble M, Seed W, editors. The interval-force relationship of the heart: Bowditch revisited. London: Cambridge University Press; 1992. p. 67–91Google Scholar
  4. Crozatier B. Force-frequency relations in nonfailing and failing animal myocardium. In: Hassenfuss G, Just H, editors. Heart rate as a determinant of cardiac function—basic mechanisms and clinical significance. Freiberg: Steinkopff Verlag Darmstadt; 2000. p. 77–9Google Scholar
  5. Eising G, Hammond K, Helmer G, Gilpin E, Ross J Jr. Force-frequency relations during heart failure in pigs. Am J Physiol 1994;267:H2516–22Google Scholar
  6. Endoh M. Force-frequency relationship in intact mammalian ventricular myocardium: physiological and pathophysiological relevance. Eur J Pharmacol 2004;500:73–86PubMedCrossRefGoogle Scholar
  7. Feldman M, Alderman J, Aroesty J, Royal H, Ferguson J, Owen R, Grossman W, McKay R. Depression of systolic and diastolic myocardial reserve during atrial pacing tachycardia in patients with dilated cardiomyopathy. J Clin Invest 1988;82:1661–9PubMedCrossRefGoogle Scholar
  8. Hoffman B, Bindler E, Suckling E. Postextrasystolic potentiation of contraction in cardiac muscle. Am J Physiol 1955;185:95–102Google Scholar
  9. Kass D. Force-frequency relation in patients with left ventricular hypertrophy and failure. Basic Res Cardiol 1998;93:108–16PubMedCrossRefGoogle Scholar
  10. Lemaire S, Piot C, Leclercq F, Leuranguer J, Nargeot J, Richard S. Heart rate as a determinant of L-type Ca2+ channel activity: mechanisms and implication in force-frequency relation. In: Hassenfuss G, Just H. Freiberg, editors. Heart rate as a determinant of cardiac function. Germany: Steinkopff Verlag Darmstadt; 2000. p. 85–95Google Scholar
  11. Neumann T, Ravens U, Heusch G. Characterization of excitation–contraction coupling in conscious dogs with pacing-induced heart failure. Cardiovasc Res 1997;37:456–66CrossRefGoogle Scholar
  12. Phillips P, Gwathmey J, Feldman M, Schoen F, Grossman W, Morgan J. Post-extrasystolic potentiation and the force-frequency relationship: differential augmentation of myocardial contractility in working myocardium from patients with end-stage heart failure. J Mol Cell Cardiol 1990;22:99–110PubMedCrossRefGoogle Scholar
  13. Ravens U, Mahl C, Hardman S, Noble M. Mechanical restitution and recirculation fraction in cardiac myocytes and left ventricular muscle of adult rats. Basic Res Cardiol 1996;91:123–30PubMedCrossRefGoogle Scholar
  14. Schwinger R, Bohm M, Muller-Ehmsen J, Uhlmann R, Schmidt U, Stablein A, Uberfuhr P, Kreuzer E, Reichart B, Eissner H-J, Erdmann E. Effect of inotropic stimulation on the negative force-frequency relationship in teh failing human heart. Circulation 1993;88:2267–76PubMedGoogle Scholar
  15. Seed W. Interval-force effects in intact hearts. In: Noble M, Seed W, editors. The interval-force relationship of the heart: Bowditch revisited, London: Cambridge University Press; 1992. p. 317–54Google Scholar
  16. Seed W, Noble M, Walker J, Miller G, Pidgeon J, Redwood D, Wanless R, Franz M, Schoettler M, Schaefer J. Relationships between beat-to-beat interval and the strength of contraction in the healthy and diseased human heart. Circulation 1984;70:799–805PubMedGoogle Scholar
  17. Shimizu J, Araki J, Iribe G, Imaoka T, Mohri S, Kohno K, Matsubara H, Ohe T, Takaki M, Suga H. Postextrasystolic contractile decay always contains exponential and alternans components in canine hearts. Am J Physiol Heart Circ Physiol 2000;279:H225–33PubMedGoogle Scholar
  18. ter Keurs H. Post-extrasystolic potentiation and its decay. In: Noble M, Seed W, editors. The interval-force relationship of the heart: Bowditch revisited. Cambridge: Cambridge University Press; 1992. p. 259–82Google Scholar
  19. Yue D. Relationships between intracellular free calcium and force with changes of interval. In: Noble M, Seed W, editors. The interval-force relationship of the heart. Cambridge: Cambridge University Press; 1992. p. 95–109Google Scholar

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • Sarah E. Ahlberg
    • 1
    • 2
  • Robert C. Hamlen
    • 4
  • Daniel L. Ewert
    • 5
  • Paul A. Iaizzo
    • 1
    • 2
    • 3
  • Lawrence J. Mulligan
    • 4
  1. 1.Department of Biomedical EngineeringUniversity of MinnesotaMinneapolisUSA
  2. 2.Department of SurgeryUniversity of MinnesotaMinneapolisUSA
  3. 3.Department of PhysiologyUniversity of MinnesotaMinneapolisUSA
  4. 4.Therapy Delivery, Medtronic, Inc.MinneapolisUSA
  5. 5.Department of Electrical and Computer EngineeringNorth Dakota State UniversityFargoUSA

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