Colour M-mode velocity propagation: a glance at intra-ventricular pressure gradients and early diastolic ventricular performance.

The physiology of early-diastolic filling comprises ventricular performance and fluid dynamical principles. Elastic recoil and myocardial relaxation rate determine left ventricular early diastolic performance. The integrity of left ventricular synchrony and geometry is essential to maintain the effect of their timely action on early diastolic left ventricular filling. These factors not only are prime determinants of left ventricular pressure decay during isovolumic relaxation and immediately after mitral valve opening; they also instigate the generation of a sufficient intra-ventricular pressure gradient, which enhances efficient early diastolic left ventricular filling. Accurate assessment of diastolic (dys)function by non-invasive techniques has important therapeutic and prognostic implications but remains a challenge to the cardiologist. The evaluation of left ventricular relaxation by the standard Doppler echocardiographic parameters is hindered by their preload dependency. The colour M-mode velocity propagation of early diastolic inflow (Vp) correlates with intra-ventricular pressure gradients and is a largely preload independent index of ventricular diastolic performance. In this article, the physiologic background, utility and limitations of this promising new tool for the study of early diastolic filling are reviewed.

Spectral pulsed tissue Doppler imaging in diastole: a tool to increase our insight in and assessment of diastolic relaxation of the left ventricle.

BACKGROUND: Conventional Doppler echocardiography offers an indirect assessment of left ventricular (LV) diastolic function, hampered by preload dependency. Tissue Doppler imaging (TDI) is a tool to study diastolic function in a more direct and less preload-dependent manner. METHODS: The Medline database has been searched for literature on TDI for the analysis of diastolic function. A secondary search reviewed the relevant references related to TDI or diastolic function in general. RESULTS: TDI measures myocardial velocities with a high temporal and velocity resolution but lacks spatial information. In particular, the velocity of early diastolic wall motion (E(m)) and its timing are promising indices of local myocardial relaxation. E(m) at the mitral annulus offers fair estimates of ventricular relaxation, relatively independent of preload and systolic function. Combined with early transmitral flow velocity (E), detection of pseudo-normalized filling patterns and estimation of filling pressures are enhanced by E/E(m). CONCLUSION: TDI has an emerging role in the study and assessment of diastolic function. However, TDI-derived information needs to be integrated with other echocardiographic data because single diagnostic accuracy remains unsatisfactory.