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Introduction and Objectives: The minimum value of dP/dT is a parameter of diastolic function that can be estimated noninvasively by analyzing the profile of velocity of the mitral regurgitant jet, recorded by continuous-wave Doppler. This estimation requires a complex analysis of the curves that impedes its practical use. Our objective was to validate a simplified method to estimate noninvasively the value of dP/dTmin when mitral regurgitation exists. We calculated the pendient of the profile of velocity of the curve of mitral regurgitation during its deceleration, between 3 and 1.5 m/s, an interval that defines a difference in pressure using the formula delta p = (4v2(1) - 4v2(2)). We divided this interval by the time needed by the jet to decelerate from 3 to 1.5 m/s, obtaining the rate of pressure decay, in mmHg/s., Methods: We provoked mitral regurgitation in five pigs and registered dP/dT and the curve velocity of mitral regurgitation simultaneously, by micromanometer-tipped catheter and continuous-wave Doppler, respectively. The rate of pressure decay was calculated on the mitral regurgitation curve., Results: We obtained 29 simultaneous registers. The coefficient for the correlationship between dP/dT and the rate of pressure decay was with an r value of 0.62 (p < 0.0001). The rate of pressure decay underestimated systematically the value of dP/dT. Intra and interobserver variability of TDP was 9 and 11%, respectively., Conclusions: This study validates a simplified method to estimate dP/dT noninvasively, with acceptable correlation with invasive measurements and adequate reproducibility.

Hypertrophic cardiomiopathy is a peculiar process with different anatomical and functional abnormalities which are present in different degrees in each case. Echocardiography and Doppler techniques have contributed definitively to the knowledge of this process and these procedures are choices for establishing the diagnosis of hypertrophic cardiomyopathy and to evaluate the clinical and morphological diversity of this process consisting of a spectrum of abnormalities with a variable presence in each case. Disproportionate septal hypertrophy is the most frecuent finding but the hypertrophy can involve other segments and different patterns can be present; concentric hypertrophy, apical, involving right ventricle, inverted asymetric, etc. Anterior mitral valve motion can be produced by the interrelation between anatomic factors of the valve, geometry of the outflow tract and physical forces produced by flow changes. Doppler echocardiography allows us to evaluate subaortic obstruction, to define its site, to demonstrate and measure the degree of mitral regurgitation and to carry out intraoperative studies. In hypertrophy cardiomyopathy the pattern of delayed relaxation is the most frequent but patients with severe obstruction and mitral regurgitation can pseudonormalize this pattern and even show restrictive patterns.