The usefulness of pulsed tissue Doppler for the clinical assessment of right ventricular function.

Standard Doppler echocardiographic evaluation of the right ventricular (RV) function has several limitations because of a difficult technical approach. The purpose of the present review was to investigate, even in the light of such problems, the usefulness of pulsed tissue Doppler (TD) during the assessment of RV transverse and longitudinal function on the basis of the regional velocities and time intervals. TD-derived (systolic and diastolic) velocities of the RV free wall and of the lateral tricuspid annulus have been used to establish reference values in healthy subjects and in different cardiac diseases. Some studies have shown the usefulness of myocardial systolic velocities for the detection of RV systolic failure at rest and of right coronary artery stenosis during stress. The myocardial early diastolic velocities, combined to Doppler standard tricuspid inflow measurements, represent reliable indexes of right chamber hemodynamics, the ratio between the Doppler tricuspid E velocity and the TD-derived early diastolic velocity of the lateral tricuspid annulus being positively related to the mean right atrial pressure after heart transplantation. Even the assessment of RV regional time intervals may have clinical implications. In particular, the relaxation time of the lateral tricuspid annulus, very short or even absent in healthy subjects increases progressively with the pulmonary systolic artery pressure and its length is strongly influenced also by the increasing RV wall thickness in septal hypertrophic cardiomyopathy and in hypertensive left ventricular hypertrophy. The interaction between the two ventricles is identified by assessing the TD velocities of the RV tricuspid annulus which are often associated with the corresponding velocities of the mitral annulus in different pathologies. On the grounds of these studies, the clinical use of pulsed TD merits consideration. Longitudinal follow-up of TD RV patterns will be useful to evaluate the progression from early RV wall dysfunction until the development of global RV failure and the possible beneficial effect of cardiac drugs on RV function as determined by TD evaluation.