[Validation of indirect myocardial parameters of oxygen consumption in patients with normal and pathologically changed ventricular function].

Five frequently used hemodynamic oxygen consumption parameters were compared with the directly measured myocardial oxygen consumption (MVO2) in 28 patients with different heart diseases (4 without heart disease, 2 with mitral valve prolapse, 20 with coronary artery disease with or without left ventricular dysfunction, 2 with mitral regurgitation, 1 with hypertrophic obstructive cardiomyopathy and 3 with left ventricular hypertrophy due to hypertension). In most patients pressure-rate product (r = 0.908), tension-time index (r = 0.977), triple product (r = 0.970), pressure-work index (r = 0.954) and the additive parameter Et (r = 0.994) correlated relatively close with MVO2 under conditions of normal or low inotropic stimulation. Already during a moderately enhanced contractile state, tension-time index (r = 0.855), triple product (r = 0.873) and pressure-work index (r = 0.906) lose their close correlations with MVO2. Only pressure-rate product (r = 0.933) and Et (r = 0.982) remained reliable predictors of MVO2 also under these conditions of moderate positive inotropic stimulation.