Normal reference values for left atrial strains and strain rates in school children assessed using two-dimensional speckle-tracking echocardiography.

Left atrium (LA) function is a known predictive marker of heart failure in adults. Few reports of LA function analyses using LA strain (ɛ) and strain rate (SR) measurements in children exist. Thus, this study aimed to determine normal reference values for LA ɛ and SR in healthy school children and to investigate methods of interpreting LA function data based on maturational changes using two-dimensional speckle-tracking echocardiography (2DSTE). We recruited 112 healthy school children (median age 12.0 years; range 6-16 years). LA ɛ and SR were investigated using 2DSTE multi-vendor analysis software (TomTec Imaging Systems, Germany) and compared to Doppler parameters and LA volumes measured by the conventional method. The onset of the P wave was selected as the reference point for the LA ɛ analysis. Normal ranges of LA ɛ [reservoir (ɛRS), conduit (ɛCD), or contractile (ɛCT)] and positive SR (SRPOS), early negative SR (SREN), and late negative SR (SRLN) were obtained using Z-score models via the lambda-mu-sigma method. According to the Z-score curves, all ɛ showed slight falling or continuous flat lines against age, body surface area (BSA), or heart rate (HR); however, ɛ CT showed modestly positive associations with HR. As for SR, the Z-score curves showed falling lines against age and BSA. In contrast, Z-score curves for SREN and SRLN showed rising lines against HR. SREN was independent of E/e' and was negatively correlated with LA volume indexed against BSA. This study demonstrated the normal reference values for LA ɛ and SR using 2DSTE in school children. The present results recommended that LA ɛ should be evaluated together with changes in LA SR for accurate assessment, considering maturational changes including age, BSA, and HR in school children.

Impact of persistent left ventricular regional wall motion abnormalities in childhood cancer survivors after anthracycline therapy: Assessment of global left ventricular myocardial performance by 3D speckle-tracking echocardiography.

AIMS: To identify left ventricular (LV) mechanical impairment by 3D speckle-tracking echocardiography (3DSTE) in long-term childhood cancer survivors after anthracycline therapy with or without persistent LV regional diastolic wall motion abnormalities (WMA) and a preserved LV ejection fraction (EF >53%). METHODS AND RESULTS: Thirty-two patients (median: 14.6 years) and 12 age-matched controls were studied. The patients were divided into two groups according to the existence of WMA: Group 1 (with WMA: n=14), Group 2 (without WMA: n=18). 3DSTE was performed to assess LV global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), global area strain (GAS), LV torsion, LV end-diastolic volume (LVEDV), and LV end-systolic volume (LVESV). LV systolic dyssynchrony index (SDI) was calculated as the percentage of the standard deviation of time to peak strain of the 16 segments divided by the RR interval. There was no significant difference in LVEDV, LVESV, GLS, torsion, or SDI derived from LS, CS, or AS among the 3 groups. In contrast, there were significant differences in GRS, GCS, and GAS, and SDI derived from RS among the 3 groups. Compared with group 2, group 1 had significantly reduced GRS (p<0.001), GCS (p<0.01), GAS (p<0.01), and greater SDI derived from GRS (p<0.01). Moreover, the existence of WMA was correlated with GRS (p<0.001), SDI derived from GRS (p<0.001), and LVEF (p=0.036). Multiple linear regression analysis identified GRS as a significant determinant of the existence of WMA (ß=0.751, p=0.001). CONCLUSION: Childhood cancer survivors with persistent LV regional WMA show a reduced LV myocardial performance compared with those without WMA, despite a preserved LVEF.

Treatment responses for disseminated intravascular coagulation in 25 children treated with recombinant thrombomodulin: a single institution experience.

INTRODUCTION: Recombinant thrombomodulin (rTM), which degrades factors Va and VIIIa by activating protein C, has been developed as a new drug for treating disseminated intravascular coagulation (DIC). MATERIALS AND METHODS: Since July 2009, we have treated 25 children with DIC using rTM (380 U/kg/day, or 130 U/kg/day for newborns) as a first-line therapy. Median duration of rTM administration was 5 consecutive days (range, 2-13 days). We employed DIC criteria of the Japan Welfare and Health Ministry. The first day on which rTM treatment was given was defined as day 1. RESULTS: Median patients age was 3 years. Underlying diseases were hematological disorders (n=13) and severe infection (n=12). Overall, 20 of the 25 patients had recovered from DIC by day 7 and 22 of the 25 patients remained alive at day 28. Median Pediatric Logistic Organ Dysfunction score improved from 11 on day 1 to 2 on day 7 (p=0.009). Laboratory data (median) on day 7 (prothrombin time (PT) ratio, 1.15; fibrin and fibrinogen degradation products (FDP), 9.6 mg/l; D-dimer, 1.6 mg/l FEU; antithrombin, 112%; protein C, 105%) were significantly improved compared to results on day 1 (PT ratio, 1.39; FDP, 21.6 mg/l; D-dimer, 6.4 mg/l FEU; antithrombin, 86%; protein C, 54%). Whereas, 5 patients failed to respond and serious bleeding events were observed in 2 newborns. CONCLUSION: The efficacy of rTM cannot be assessed from the present dataset, due to several limitations such as the small heterogenous patient cohort, and the lack of age- and disease-matched controls. Nevertheless, this case-series remains important in terms of enabling further prospective control studies to evaluate the efficacy of rTM in children.