Left Ventricular Torsion and Strain in Patients with Repaired Tetralogy of Fallot Assessed by Speckle Tracking Imaging

Background: In patients with tetralogy of Fallot (TOF), left ventricular (LV) dysfunction is an important factor associated with poor clinical outcome. Objective: The purpose of this study was to investigate the torsion and multidirectional strain of the LV in patients with TOF. Methods: Echocardiographic images were prospectively acquired in 29 patients who underwent TOF repair (age range, 5–25 years) and in 29 normal controls. Torsion and circumferential and longitudinal strain of the LV were assessed using speckle tracking imaging. Results: The torsion in patients was smaller compared to that in the controls due to small apical rotation and/or inverse basal rotation (P < 0.01). Torsion and untwisting rates decreased with increasing age (R = 0.37, P < 0.05). Basal circumferential strain and strain rate (SR) at systole and diastole decreased with age (R = 0.58; R = 0.57; R = 0.57, all P < 0.001) and were smaller in patients compared to those in the controls (all P < 0.01). Septal longitudinal strain and SR at systole and diastole decreased with age (R = 0.52; R = 0.62; R = 0.71, all P < 0.001) and were smaller than those of the controls (P < 0.01), although lateral longitudinal strain and SR were relatively maintained. Conclusion: Abnormal torsion and strain pattern of the LV were observed in patients without symptoms of cardiac failure. Assessment of torsion and strain is a very sensitive tool to detect the early deterioration of LV function in patients with TOF. (Echocardiography 2011;28:720-729)