QUANTIFICATION OF RIGHT VENTRICULAR FUNCTION IN ATRIAL SEPTAL DEFECT USING ULTRASOUND- BASED STRAIN RATE IMAGING

Objective To study the validation of ultrasound-based strain rate imaging in the quantitative assessment of right ventricular （RV） function in atrial septal defect （ASD）. Methods Tissue Doppler images （TDI） of RV longitudinal and short axes were recorded from the apical 4-chamber view and the subcostal short-axis view in 18 normal controls, 28 children with ASD and 14 children after Amplazter closure of ASD respectively. Peak systolic velocities （ V）, peak systolic strain rates （SR）, peak systolic strains （S） at the basal segment, middle segment of RV lateral wall and the basal septum from the longitudinal axis, the middle segment of RV free waU from the short axis were quantitatively measured using QLAB^TM tissue velocity quantification software system respectively. Peak dp/ dt from the RV isovolumic contraction determined during the right cardiac catheterization in 28 ASD patients was used as the gold standard of RV contractility. Peak systolic indices were compared against max dp/dt by linear correlation, Results Peak systolic indices at the basal and middle segments of RV lateral wall from the longitudiual axis increased significantly in 28 ASD patients. Peak systolic indices at the basal septum also increased in patient group, but not significantly. Significant decreases in peak systolic indices at the basal and middle segments of RV lateral wall were observed after the Amplatzer closure in 14 ASD patients. There was no significant difference at the middle segment of RV free wall from the short axis between patient group and normal control. A strong correlation was found between max dp/dt and peak systolic indices at the basal and middle segments of RV lateral wal l （ P 〈 0. 05 ）. Conclusion Ultrasound-based strain rate imaging can assess quantitatively RVfunction in CHD. Peak systolic strains determined at the basal and middle segments of RV lateral wall are strong noninvasive indices of RV contractility.

Projecting the Right Image

The 2008 Olympic Games in Beijing will provide a good opportunity to boost China’s public relations industry It seems like an impossible mission to enable a foreigner to experience China’s 5,000-year history in just a few hours,but Mark Zhou, a Chinese, and Alex Koi, a Singaporean, have done just that.In an effort to enable people to get to know China, they have launched “urban safari” activities, in which the participants in a simulated environment can enjoy all kinds of food, videotapes and a detailed explanation to get an intimate feel of China’s history, culture, arts and folk customs in just six hours.