Quantification of regional right and left ventricular function by ultrasonic strain rate and strain indexes after surgical repair of tetralogy of fallot

Abstract

The quantification of regional myocardial function in tetralogy of Fallot (TOF) by conventional M-mode and 2-dimensional echocardiography is difficult because of the complex right ventricular (RV) and altered left ventricular (LV) geometry. In 30 asymptomatic postoperative TOF patients (aged 4 to 16 years) with a low pressure in the right ventricle and with varying degrees of pulmonary regurgitation and in 30 aged-matched healthy children, the ultrasonic-derived regional deformation parameters peak systolic strain rate (SR) and systolic strain (ϵ) were acquired from ventricles and compared. In TOF RV free walls, SR, and ϵ were reduced in the basal, mid-, and apical segments and averaged –1.5 ± 0.6 second−1 for SR and –22 ± 8% for ϵ, respectively (p <0.001 vs normals). Peak systolic SR of the basal RV free wall correlated significantly with the QRS duration of the electrocardiogram (r = 0.81, p <0.0001). Abnormalities in RV deformation were more marked in patients with transannular patches versus infundibular patches. In the septum there was a homogenous reduction in SR and ϵ in the basal, mid-, and apical segments. These averaged –1.4 ± 0.3 second−1 for SR and –19 ± 4% for ϵ, respectively (p <0.01 vs normals). Longitudinal SR and ϵ values of the 3 LV lateral wall segments (averaged SR = −1.6 ± 0.4 second−1, averaged ϵ = −20 ± 5%; p <0.05 vs normals), and radial SR and ϵ of the LV posterior wall (SR = 3.3 ± 0.9 second−1; ϵ = 51 ± 14%; p <0.05 vs normals) were significantly reduced. Thus, abnormalities in regional RV and LV systolic myocardial function in asymptomatic postoperative TOF patients were quantified by the deformation parameters SR and ϵ. RV deformation abnormalities are associated with electrical depolarization abnormalities.