Clinical significance of positive isovolumetric relaxation velocity of pulsed-wave tissue Doppler imaging.

Objective: Among the pulsed-wave tissue Doppler imaging (pw-TDI) parameters, there are two different pw-TDI velocities (IVRa and IVRb) after systolic velocity, but before Ea velocity. In our study, we investigated the clinical importance of these two velocities in left ventricular diastolic dysfunction (LVDDF) evaluation.

Methods: One hundred and eighty cases without exclusion criteria were included in the study. Cases with a transmitral E to A flow (E/A) ratio below 1 were assigned to group 2. In cases with an E/A ratio between 1 and 2, the pw-TDI parameters were taken into consideration. Cases with an Ea/Aa ratio above 1 were assigned to group 1 and cases with an Ea/Aa ratio 1 or below than 1 were assigned to group 3. Group 1 (n: 68) represented normal diastolic left ventricular (LV) inflow while group 2 (n = 87) represented impaired relaxation and group 3 (n = 25) represented pseudonormal LV inflow.

Results: In our study, we found that IVRa velocity was lower in group 1 compared to group 2 and group 3 (P < 0.001 and P = 0.038, respectively). Similarly, this velocity was significantly different in group 3 and group 2 such as it was higher in group 2 compared to group 3 (P = 0.022). There was no difference in IVRb velocity and IVRa/IVRb ratio among the groups. A negative correlation was found between IVRa velocity and Ea velocity (r = 44%, P < 0.001). Positive correlation was found between IVRa velocity and isovolumetric relaxation time (r = 18%, P = 0.014) and also between IVRa velocity and Aa velocity (r = 19%; P = 0.010).

Conclusion: Based on the results of our study, we concluded that IVRa velocity is an important pw-TDI parameter in the evaluation of LVDDF, especially in differentiating pseudonormal LVDDF type from normal LV inflow.