Real-Time Transthoracic Three Dimensional Echocardiography: Normal Reference Data for Left Ventricular Dyssynchrony in Adolescents

Abstract

Since the introduction of cardiac resynchronization therapy, the assessment of left ventricular (LV) dyssynchrony has become increasingly important. Real-time three-dimensional echocardiography (RT-3DE) is one of the methods that is increasingly used. However, normal reference data in a young population are scarce. RT-3DE was performed in 73 healthy adolescents aged 12 to 18 years. A systolic dyssynchrony index was derived from the dispersion of time to minimum regional volume for all 16 LV segments. Acquisition of RT-3DE data sets was feasible in 67 of 73 subjects (92%). LV end-diastolic volume and LV end-systolic volume were 99+/-25 and 41+/-15 mL, respectively. All controls had highly synchronized segmental function (systolic dyssynchrony index, 1.26+/-0.53%). Dyssynchrony was independent of age, weight, or length. Interobserver variability for the dyssynchrony index was 2+/-2 ms and 0.3+/-0.2% for the absolute and heart rate-corrected values, respectively. Intraobserver variability was 2.0+/-0.07 ms and 0.0+/-0.27%, respectively. RT-3DE could be performed in most healthy adolescents with good interobserver and intraobserver variability. Highly synchronized segmental function was present and was independent of age, weight, or length.