Tissue Doppler to Assess Diastolic Left Ventricular Function.
Doppler indices of left ventricular (LV) filling have been used traditionally for the assessment of LV diastolic function. In many circumstances, however, the interpretation of these indices is difficult because they respond to alterations of different physiological variables such as preload, relaxation, and heart rate. A typical example of their limitation is seen in patients with abnormal LV relaxation and increased preload compensation, who often present a "pseudonormal" LV filling pattern. Thus, there is a need for noninvasive indices of diastolic function capable of discriminating the effects of relaxation and preload. Tissue Doppler echocardiography (TDE) is available in most modern cardiac ultrasound imaging systems. TDE can be used to obtain regional myocardial velocities during isovolumic relaxation, early filling, and atrial systole with high spatial and temporal resolution. This article discusses the complementary role, limitations, and future challenges of TDE in the study of diastolic function.