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

Background: 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. Methods: 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. Results: 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. Conclusions: 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. (J Am Soc Echocardiogr 2009; 22: 933-8.)