Utility of Doppler echocardiography and tissue Doppler imaging in the estimation of diastolic function in heart failure with normal ejection fraction: a comparative Doppler-conductance catheterization study - Kasner, M; Westermann, D; Steendijk, P; Gaub, R; Wilkenshoff, U; Weitmann, K; Hoffmann, W; Poller, W; Schultheiss, H P; Pauschinger, M; Tschöpe, C (Circulation, 2007)