Differentiation of the Left and Right Side Interventricular Septum Function in Healthy Subjects by Vector Velocity Imaging

Abstract

Background: The present study aimed to assess and compare regional strain of the right and left sides of interventricular septum in healthy subjects using velocity vector imaging analysis due to the importance of interventricular septum and limited basic information about the exact function of the interventricular septum. Methods: The present study was conducted on 40 healthy subjects. Echocardiography was performed in the apical 4-chamber view in the left lateral decubitus position. Image analysis was done offline with velocity vector imaging; the longitudinal strain and strain rate were calculated during 3 cardiac cycles. Strain-time and strain rate-time curves in basal, middle, and apical segments of the left and right sides of interventricular septum were recorded; peak values and time to peak strain were determined. Results: There was no significant difference between the longitudinal strain in the right and left basal (−17.7 +- 5.10% vs. −18.2 +- 5.14%, P=.550), middle (−17.1 +- 4.53% vs. −17.9 +- 4.29%, P =.197) segments, strain rate of basal (−1.1 +- 0.36 1/s vs. −1.0 +- 0.36 1/s, P =.350), and middle (−1.0 +- 0.30 1/s vs. −1.1 +- 0.32 1/s, P =0.551) segments. However, there was a significant difference between the longitudinal strain (−22.2 +- 5.55% vs. −16.6 +- 4.45%, P <.001) and strain rate (−1.5 +- 0.46 1/s vs. −1.1 +- 0.33 1/s, P <.001) of the apical segment. Time to peak strain was significantly different only in the middle segment of interventricular septum (right side: 351.0 +-11.5 ms vs.left side: 344.4 +- 13.1 ms, P =.004). Conclusions: The findings of this study suggest that the right and left function of the septum was comparable in the basal and middle segments of healthy subjects; this function was significantly different in the apical segments.

Keywords

• healthy volunteers
• heart
• ventricular septum
• cardiac imaging technique
• mechanical phenomena