In general, pump function and myocardial contractility should be assessed when evaluating left ventricular (LV) systolic function. Ejection fraction obtained from left ventriculography is routinely used as an index of pump function, and the maximum value of the first derivative of LV pressure curve (peak dP/dt) has been used as an index of myocardial contractility. On the other hand, active relaxation of the LV myocardium during early diastole and LV passive filling or compliance during mid-to late diastole are important factors in evaluating LV diastolic function. To obtain this information, the time constant of the LV pressure decay during isovolumic diastole (tau) and LV end-diastolic pressure, which are calculated from the LV pressure curve recorded during cardiac catheterization, is used. However, invasive hemodynamic measurements cannot be performed in all patients, nor are they appropriate for follow-up evaluation involving repeated examinations.Recently, routine echocardiography has facilitated the noninvasive evaluation of LV systolic and diastolic function. The percent fractional shortening of the LV based on M-mode echocardiography and the LV ejection fraction determined by two-dimensional echocardiography are indices of LV pump function, and therefore cannot accurately evaluate LV myocardial contractility. On the other hand, "diastology" has become an important clinical topic [1]. There are several reasons why assessment of diastolic function is important: 1) 30 to 40% of patients evaluated for congestive heart failure have normal LV pump function [2,3]; 2) the transmitral flow velocity pattern, which is recorded using the pulsed Doppler method, may be an index for noninvasive evaluation of LV diastolic function [4]; and 3) the prognosis is poor in patients with LV systolic dysfunction and pseudonormalization or restrictive pattern of the transmitral flow velocity [5,6]. However, it has been shown that the diastolic indices obtained from transmitral and pulmonary venous flow velocities are influenced by loading conditions, especially by the pre-
The Role of Tissue Doppler Imaging as a New Diagnostic Option in Evaluating Left
AbstractThe widespread use of the pulsed Doppler echocardiography has facilitated the noninvasive evaluation of hemodynamic abnormalities of the left atrium and left ventricle (LV) based on transmitral and pulmonary venous flow velocity patterns. However, it has been shown that loading conditions, especially preload, influence the indices obtained from these velocity patterns. Recently, tissue Doppler imaging (TDI) has been applied to the clinical setting to assess LV myocardial function. In particular, this procedure has the following characteristics: 1) it can provide circumferential and longitudinal information for the LV myocardium; 2) the early diastolic LV myocardial parameters determined by TDI are not influenced by preload; 3) LV myocardial contractility can be evaluated from the early systolic parameters; 4) LV systolic and diastolic asynchrony can be detected; 5) myoca...