Surgery – Diagnostic testing – Cardiovascular
Reexamination Certificate
2002-08-01
2004-06-01
Hindenburg, Max F. (Department: 3736)
Surgery
Diagnostic testing
Cardiovascular
C600S481000, C604S096010, C604S097010, C604S099040
Reexamination Certificate
active
06743181
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to measuring ventricular function.
Ventricular function is often measured by researchers in an isolated heart, such as an isolated rat heart. The use of an isolated heart allows a broad spectrum of biochemical, physiological, morphological, and pharmacological indices to be measured without the presence of confounding effects of other organs, the systemic circulation, and peripheral complications. One method that researchers often use is the Langendorff method. In the Langendorff method, a balloon attached to a cannula is inserted into the heart and attached to a reservoir containing oxygenated perfusion fluid. The fluid is delivered down the aorta in a retrograde direction at either a constant flow rate or at a constant hydrostatic pressure. The aortic valves are forced shut and the perfusion fluid is directed into the coronary ostia, perfusing the entire ventricular mass of the heart and draining into the right atrium via the coronary sinus.
Although the size of an isolated heart changes under many conditions, such as with ischemia, reperfusion, or drug treatment, in the traditional Langendorff method, any changes in the size of the heart are not taken into account. The result is the incorporation of a systematic error into repeated measurements of ventricular function following interventions. The present invention takes the changing size of the heart into account in calculating ventricular function, yielding accurate measurements.
SUMMARY OF THE INVENTION
In one embodiment, the invention relates to a method of measuring ventricular function in an isolated, perfused heart using an intraventricular balloon connected to a plumbing circuit containing a fluid, the plumbing circuit including (a) a valve for selectively opening the plumbing circuit to (i) atmospheric pressure or (ii) a pressure control circuit of a pressure control apparatus or (b) a pressure control apparatus which can be selectively connected to the plumbing circuit, including the steps of establishing a base pressure by (1) opening the valve to atmospheric pressure or the pressure control circuit or (2) operating the pressure control apparatus, after equalization of the pressure within the intraventricular balloon with the base pressure, closing the valve or stopping operation of the pressure control apparatus, following the closing of the valve, measuring ventricular function as a function of a titrated infusion of fluid into the plumbing circuit and intraventricular balloon, performing an intervention, and repeating at least the first three steps.
In another embodiment, the invention relates to a system for measuring ventricular function in an isolated, perfused heart, including an intraventricular balloon adapted to be inserted into the isolated heart, a plumbing circuit containing a fluid, connected to the intraventricular balloon, a pressure transducer connected to the plumbing circuit, a pump, and a three-way valve connected to the plumbing circuit, the pump, and to the atmosphere, wherein opening the three-way valve to the atmosphere causes atmospheric pressure to be exerted by the intraventricular balloon on the isolated heart, and wherein subsequently opening the three-way valve to the pump causes the pressure exerted by the intraventricular balloon on the isolated heart to be equal to the sum of the atmospheric pressure and the pressure exerted by an infused volume of fluid.
REFERENCES:
patent: 4116589 (1978-09-01), Rishton
patent: 6241706 (2001-06-01), Leschinsky et al.
patent: 6245008 (2001-06-01), Leschinsky et al.
Alanen, K. et al., “Ischaemic Contracture and Myocardial Perfusion in Isolated Rat Heart”, Virchows Arch. A Path. Anat. and Histol., vol. 385, pp. 143-149 (1980).
Alanen, K.A. et al., “Effect of verapamil on reperfusion damage and calcium paradox in isolated rat heart”, Exp. Path., vol. 25, pp. 131-138 (1984).
Berrebi-Bertrand, I. et al., “Inotropic effect of ouabain in hypertrophied rat heart”, Pflügers Arch., European Journal of Physiology, vol. 417, pp, 247-254 (1990).
Brooks, W.W. et al., “Oxygen Cost of Stress Development in Hypertropheid and Failing Hearts From the Spontaneously Hypertensive Rat”, Hypertension, vol. 21, No. 1, pp. 56-64 (1993)
Cave, A.C. et al., “ATP Synthesis During Low-Flow Ischemia: Influence of Increased Glycolytic Substrate”, Circulation, vol. 101, pp. 2090-2096 (2000).
Chevalier, B. et al., “Diminished toxicity of ouabain in the hypertrophied rat heart”, Pflügers Arch., European Journal of Physiology, vol. 414, pp. 311-316 (1989).
Chevalier, B. et al., “Screening of Inotropic Drugs on Isolated Rat and Guinea Pig Hearts”, Journal of Pharmacological Methods, vol. 17, pp. 313-326 (1987).
Daniels, M. et al., “Velocity of Sarcomere Shortening in Rat Cardiac Muscle: Relationship to Force, Sarcomere Length, Calcium and Time”, J. Physiol., vol. 355, pp, 367-381 (1984).
Docherty, J.C. et al., “An inhibitor of poly (ADP-ribose) synthetase activity reduces contractile dysfunction and preserves high energy phosphate levels during reperfusion of the ischaemic rat heart”, British Journal of Pharmacology, vol. 127, pp. 1518-1524 (1999).
Döring, H.J., “The Isolated Perfused Heart According to Langendorff Technique—Function—Application”, Physiologie Bohemoslovaca, vol. 39, pp. 481-504 (1990).
Eberli, F.R. et al., “Exacerbation of Left Ventricular Ischemic Diastolic Dysfunction by Pressue-Overload Hypertrophy: Modification by Specific Inhibition of Cardiac Angiotensin Converting Enzyme”, Circulation Research, vol. 70, No. 5, pp. 931-943 (1992).
Falsetti, H.L. et al., “Analysis and Correction of Pressure Wave Distortion in Fluid-Filled Catheter Systems”, Circulation, vol. 49, pp. 165-172 (1974).
Gao, F. et al., “Mechanism of decreased adenosine protection in reperfusion injury of aging rats”, Am. J. Physiol. Heart Circ. Physiol., vol. 279, pp. H329-H338 (2000).
Glantz, S.A. et al., “Determination of frequency response from step response: application to fluid-filled catheters”, American Journal of Physiology, vol. 236, pp. H376-H378 (1979).
Grover, G.J. et al., “Glyburide-reversible cardioprotective effect of BMS-180448 is independent of action potential shortening”, Cardiovascular Research, vol. 30, pp. 731-738 (1995).
Grover, G.J. et al., “Glyburide-Reversible Cardioprotective Effects of BMS-180448: Functional and Energetic Considerations”, Journal of Cardiovascular Pharmacology, vol. 29, pp. 28-38 (1997).
Guppy, L.J. et al., “Effect of Calcium, Bay K 8644, and Reduced Perfusion on Basic Indices of Myocardial Function in Isolated Hearts from Rats After Prolonged Exposure to Ethanol”, Journal of Cardiovascular Pharmacology, vol. 34, pp. 480-487 (1999).
Harding, S.E. et al., “Contractile Responses of Isolated Adult Rat and Rabbit Cardiac Myocytes to Isoproterenol and Calcium”, J. Mol. Cell Cardiol., vol. 20, pp. 635-647 (1988).
Hata, Y. et al., “Linear O2Use—Pressure-Volume Area Relation from Curved End-Systolic Pressure—Volume Relation of the Blood-Perfused Rat Left Ventricle”, Japanese Journal of Physiology, vol. 48, pp. 197-204 (1998).
Humphrey, S.M. et al., “The Effect of an Isovolumic Left Ventricle on the Coronary Vascular Competence during Reflow after Global Ischemia in the Rat Heart”, Circulation Research, vol. 49, No. 3, pp. 784-791 (1981).
Humphrey, S.M. et al., “The Influence of the No-Reflow Phenomenon on Reperfusion and Reoxygenation Damage and Enzyme Release from Anoxic and Ischaemic Isolated Rat Hearts”, J. Mol. Cell Cardiol., vol. 16, pp. 915-930 (1984).
Inagaki, K. et al., “Anti-Ischemic Effect of a Novel Cardioprotective Agent, JTV519, Is Mediated Through Specific Activation of &dgr;-Isoform of Protein Kinase C in Rat Ventricular Myocardium”, Circulation, vol. 101, pp. 797-804 (2000).
Inarejo, M. et al., “Effects of Catecholamine Uptake Inhibitors on the Positive Inotropic Responses to Isoprenaline, Dobutamine and Dopexamine in Human, Rat and Guinea-Pig Atrial Heart Muscle”, Arch. int. Pharmacodyn., vol. 323, pp. 50-61 (1993).
Inserte, J. et al., “Urodilatin limits acute reperfusion injury in the iso
Bristol-Myers Squibb Co.
Davis Stephen B.
Hindenburg Max F.
Natnithithadha Navin
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