Color M-mode for the assessment of left ventricular diastolic function

ABSTRACT

During the last two decades, Doppler echocardiography has emerged as the principal clinical tool for the assessment of left ventricular [LV] diastolic function. Trans-mitral and pulmonary venous Doppler flow indices have been used to evaluate different parameters of diastolic function, but it is difficult to use these modalities in differentiation between a normal filling pattern and a pseudo-normal filling pattern. Recently, color M-mode [CMM] of LV inflow and tissue Doppler imaging [TDI] of mitral annulus have provided additional insights in the assessment of diastolic function. Aim of the work was to correlate the new parameter CMM of LV inflow with trans-mitral flow [TMF] in different patterns of diastolic performance to evaluate its clinical utility. 70 patients [46 males, and 24 females] who are having diseases known to affect diastolic function and 10 normal individuals as a control group were included in the study. The 70 patients were divided into 3 groups according to their LV diastolic filling pattern based on the conventional TMF pattern and included, group I [impaired relaxation pattern, IR], group 2 [pseudo-normal pattern, PN] and group 3 [restrictive filling pattern. RFP]. All of them were subjected to trans-thoracic Doppler echocardiography [TTE] with TMF and CMM examinations. In group I [IR], flow propagation velocity [VP] was lower than that in PN and control groups but higher than that in RFP group. Time delay [TD] and E/VP ratio were lower than those in PN and RFP groups but higher than those in control group. In group 2 [PN], VP and TD were higher than those in IR and RFP groups but lower than those in control group. E/VP was higher than that in IR and control groups but lower than that in RFP. In group 3 [REP], VP was lower than that in all other groups. TD and E/VP were higher than those in all other groups. Tei index was significantly higher in group 2 and 3 as compared to the control group but did not show significant change between group 1 and the control group. Also there was statistically significant correlation between E/VP ratio with, E, TD and Tei index. While statistically significant negative correlation was recorded between E/VP ratio with EDT, IVRT and VP. The new modality CMM is helpful in differentiation of PN pattern from normal pattern and can be complementary to TMF to give an idea non-invasively about diastolic parameters