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

Abstract

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.