[Validation of indirect myocardial parameters of oxygen consumption in patients with normal and pathologically...

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.