title: Method for computation of cardiac output in mitral stenosis independent of left ventricular dimensions and kinetic state: correlation with cardiac catheterization via the Fick method.
abstract: An hydraulic orifice formula offering the possibility of quantifying cardiac output in conditions of mitral stenosis is tested using potentially noninvasive portions of catheterization data from patients evaluated for obstructive mitral valve disease. The equation studied is V = (1/21) R A T2, where V is the cardiac output (ml/min), R is the heart frequency, A is the mitral valve area (cm2), and T is the diastolic filling interval (sec/min). The mitral valve area was determined by the Gorlin formula, and R and T were measured from the pressure tracings recorded at cardiac catheterization. The degree of correspondence between the equation tested and the measured cardiac output as determined by the Fick principle technique is characterized by r = 0.87, SE = 450 ml/min, N = 10. The results suggest that the new formulation may offer a noninvasive method for estimating the cardiac output status of patients with mitral valve disease once mitral valve area is measured either at catheterization or by two-dimensional echocardiography.
mesh_terms: D006328:Cardiac Catheterization; D002302:Cardiac Output; D004452:Echocardiography; D006801:Humans; D008433:Mathematics; D008946:Mitral Valve Stenosis / Q000473:pathology / Q000503:physiopathology*