| Tissue Doppler imaging of the long axis motion of the heart and the flow propagation velocity are newer non-invasive methods based on Doppler echocardiography which have been developed recently for the assessment of left ventricular diastolic function. It is not clear if these techniques are superior in clinical practice over conventional methods which are based on the patterns of mitral inflow velocities, and whether they are affected by other factors such as age, gender, heart rate, and the degree of systolic function. Therefore, the aim of this study was to determine the usefulness of these indices compared to the standard methods to determine the main factors affecting these newer indices and whether they are able to predict prognosis in a variety of cardiovascular diseases. In addition the impact of systolic function on diastolic function measured by left ventricular long axis changes was evaluated.;518 normal subjects and patients with a variety of cardiovascular diseases were studied with full 2D Doppler echocardiographic studies including measurement of left ventricular long axis changes in systole and diastole by tissue Doppler imaging and atrio-ventricular plane displacement, propagation velocity, mitral inflow velocities, pulmonary venous velocities, ejection fraction and chamber dimensions by M-mode echocardiography.;Long axis systolic and early diastolic velocities and amplitudes decreased with aging, while the late diastolic (atrial) velocity and amplitude increased with aging. Both the velocity and amplitude in systole and in early diastole correlated with left ventricular ejection fraction and short axis fractional shortening even when corrected for age, heart rate and gender.;Tissue Doppler imaging is a very useful technique for assessing left ventricular long axis function and the early diastolic mitral annular velocity appears to be a particularly sensitive marker of mildly impaired function both diastolic and systolic. Furthermore, a close link between contraction and relaxation, especially during early diastole, was revealed. Early diastolic function is, therefore, very dependent on the previous systole. This study also found that even in those with an apparently 'normal' left ventricular ejection fraction ventricular long axis function is frequently impaired. In addition, the early diastolic long axis velocity is a strong independent predictor of cardiac mortality and it appears to be a very informative measurement. However, in contrast, the flow propagation velocity as measured by the standard method does not provide any more diagnostic value than the usual mitral Doppler inflow velocities. (Abstract shortened by UMI.). |
