Usefulness of Right Ventricular Free Wall Strain Obtained with Two-Dimensional Speckle-Tracking Echocardiography in Patients with Repaired Tetralogy of Fallot and Pulmonary Regurgitation

Usefulness of Right Ventricular Free Wall Strain Obtained with Two-Dimensional Speckle-Tracking Echocardiography in Patients with Repaired Tetralogy of Fallot and Pulmonary Regurgitation

Junko Fujiwara,^1,2 Shunsuke Tatebe,³ Kotaro Nochioka,³ Hideki Ota,⁴ Yasuharu Funamizu,² Takashi Miki,² Yoshikatsu Saiki,⁵ Satoshi Yasuda³ and Yoshifumi Saijo¹

¹Biomedical Imaging Laboratory, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
²Physiological Laboratory Center, Tohoku University Hospital, Sendai, Miyagi, Japan
³Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
⁴Department of Diagnostic Radiology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
⁵Department of Cardiovascular Surgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan

Right ventricular (RV) dysfunction caused by chronic pulmonary regurgitation (PR) is a major determinant of clinical outcome in adults with repaired tetralogy of Fallot (rTOF). However, the accurate assessment of RV function by conventional echocardiography remains challenging. This study tested the feasibility and usefulness of RV free-wall (RVFW) strain obtained by two-dimensional (2D) speckle-tracking echocardiography (STE) in evaluation of RV function in adults with rTOF by comparing cardiac magnetic resonance (CMR) imaging. We enrolled 22 consecutive patients (male/female, 8/14; mean age, 25.0 years) with rTOF who underwent transthoracic echocardiography at Tohoku University Hospital from July 2016 to June 2019. We measured RVFW strain by STE and compared them with 22 hemodynamically normal subjects (NOR) (male/female, 9/13; mean age, 32.0 years). The correlation between RV strain and CMR-derived RV ejection fraction (RVEF) or PR fraction (PRF) were also evaluated. All rTOF patients had more than moderate PR but were near asymptomatic. RVFW longitudinal strain (RVFW-LS) was significantly decreased in the rTOF group compared with that in the NOR group (−19.6 vs. −24.7, P < 0.01). In the rTOF group, RVFW-LS correlated with PRF (r = 0.44, P < 0.05), whereas RVFW circumferential strain at the mid-ventricular level correlated with RVEF (r = 0.57, P < 0.01). Intra-observer variability of RVFW strain was acceptable. These results indicate that RV systolic function and PR severity in rTOF could be assessed by RVFW strain measured by 2D STE. This method is feasible and can be used as a complement to CMR imaging.

Keywords —— right ventricular free-wall strain; right ventricular function; tetralogy of Fallot; two-dimensional speckletracking echocardiography

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Tohoku J. Exp. Med 2022, 257, 7-15.

Correspondence: Yoshifumi Saijo, M.D., Ph.D., Biomedical Imaging Laboratory, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8574, Japan.

e-mail: saijo@ tohoku.ac.jp