The Pressure-Volume Relation
The ventricular pressure-volume relation, is an important presentation of global cardiac pump function. With every heart beat a full pressure-volume loop is described. When ventricular filling is changed, another loop starting from a different End-Diastolic Pressure and End-Diastolic Volume is described. The left top corners of the pressure-volume loops, i.e., the End-Systolic points, when interconnected, and approximated with a straight line give the End-Systolic Pressure-Volume relation, ESPVR, with its slope called Ees. The Ees is independent of the (arterial) load and determined by systolic muscle properties (contractility) and wall mass. The Diastolic Pressure-Volume Relation is found by connecting the End-Diastolic Pressure and Volume points. The relation depends on diastolic muscle properties and wall thickness; the relation has considerable curvature but can be fitted with an exponential relation and its slope at end-diastole is End-Diastolic Elastance, Ed. Filling changes in vivo can be obtained by partial vena cava occlusions. So-called ‘single beat’ methods have been developed to derive Ees and Ed.
KeywordsPressure-Volume loop End-Systolic Elastance End-Diastolic Elastance Frank-Starling Hypertrophy Single beat method
- 2.Sagawa K, Maughan WL, Suga H, Sunagawa K. Cardiac contraction and the pressure-volume relationship. NewYork/Oxford: Oxford University Press; 1988.Google Scholar
- 9.Klotz S, Hay I, Dickstein ML, Yi GH, Wang J, Maurer MS, et al. Single-beat estimation of end-diastolic pressure-volume relationship: a novel method with potential for noninvasive application. Am J Phys. 2006;291:H403–12.Google Scholar
- 14.Paulus WJ, Tschöpe C, Sanderson JE, Rusconi C, Flachskampf FA, Rademakers FE, et al. How to diagnose diastolic heart failure: a consensus statement on the diagnosis of heart failure with normal left ventricular ejection fraction by the heart failure and echocardiography associations of the European society of cardiology. Eur Heart J. 2007;20:2539–50.CrossRefGoogle Scholar
- 16.Westerhof N. Cardio-vascular interaction determines pressure and flow. In: Jaffrin MY, Caro CG, editors. Biological flows. New York: Plenum Press; 1995.Google Scholar
- 17.Claessens TE, Georgakopoulos D, Afanasyeva M, Vermeersch SJ, Millar HD, Stergiopulos N, et al. Nonlinear isochrones in murine left ventricular pressure-volume loops: how well does the time-varying elastance concept hold? Am J Phys. 2006;290:H1474–83.Google Scholar