Left ventricular diastolic dysfunction in end-stage dilated cardiomyopathy: simultaneous Doppler echocardiography and hemodynamic evaluation

Abstract

Left ventricular diastolic dysfunction is an integral component of end-stage dilated cardiomyopathy. To better characterize this disorder we studied 15 patients undergoing catheterization during cardiac transplant screening evaluation. Pulsed-wave Doppler echocardiographic recordings of mitral inflow were obtained with simultaneous high-fidelity left ventricular and phase-corrected pulmonary capillary wedge pressures. Doppler-derived isovolumic relaxation times were within normal limits, despite a prolonged coefficient of relaxation (tau), and correlated with pulmonary capillary wedge--left ventricular crossover pressure. Peak velocity of early diastolic filling was similar to that reported in normal subjects and did not correlate with crossover pressure or tau. Early diastolic acceleration and deceleration times were shortened compared with reported normal values. Acceleration time correlated with mean negative dP/dt from mitral valve opening to left ventricular minimum pressure and with crossover pressure, and deceleration time correlated with mean dP/dt from left ventricular minimum pressure to the peak of the rapid filling wave. Late diastolic filling at atrial contraction was absent in 12 patients, all of whom had a significant early diastolic rapid filling wave and an elevated end-diastolic pressure. Despite an increase in pulmonary capillary wedge pressure during atrial contraction, the failing ventricles were unable to generate detectable forward transmitral flow. Poor cardiac pump function was shown by low left ventricular stroke volume, which correlated with the diastolic flow velocity integral. Thus, in end-stage cardiomyopathy, the transmitral flow velocity pattern is characterized by normal peak early filling velocity, low normal isovolumic relaxation time, shortened acceleration and deceleration times of early diastolic flow, decreased early flow velocity integral, and absent or decreased filling during atrial contraction. This pattern reflects interaction between elevated transmitral driving pressure and the compromised relaxation and compliance of a left ventricle functioning on an elevated pressure-volume curve.