Normal Reference Values and z Scores of the Pulmonary Artery Acceleration Time in Children and Its Importance for the Assessment of Pulmonary Hypertension.

BACKGROUND: Pulsed-wave Doppler determination of the pulmonary artery acceleration time (PAAT) as a surrogate for pulmonary artery pressure was found to be of clinical value for assessment of pulmonary hypertension (PH) with studies to date exclusively performed in adults. This study aims to provide representative, normal reference values for PAAT in children of all ages. Moreover, we validated abnormal PAAT values in 54 children with PH. METHODS AND RESULTS: We conducted a prospective echocardiographic study in 756 healthy children (aged 1 day to 18 years) and in 54 children with PH. Possible associations of age, body length, body weight, body surface area, and heart rate on PAAT were investigated. The PAAT correlated positively with age (r=0.848), body length (r=0.871), body surface area (r=0.856), and body weight (r=0.825) and negatively with heart rate (r=-0.906). PAAT increased with age (neonates: median: 81 ms, range: 53-104; 18th year of life: median: 151 ms, range: 107-187). Receiver operating characteristic analysis for detecting PH patients using age-specific z scores showed an excellent performance of PAAT (P<0.001; area under the curve, 0.98; 95% confidence interval, 0.97-0.99) with a best cutoff score according to Youden index of -1.565 (sensitivity: 92%, specificity: 96%). PAAT values of PH patients negatively correlated (ρ=-0.497) with pulmonary vascular resistance. CONCLUSIONS: The PAAT normal reference values and z scores we provide here will be useful to identify children with a shortened PAAT. Abnormal PAAT values with scores <-2 were predictive of PH.

Right Ventricular Outflow Tract (RVOT) Changes in Children with an Atrial Septal Defect: Focus on RVOT Velocity Time Integral, RVOT Diameter, and RVOT Systolic Excursion.

OBJECTIVE: Aim of the study was to determine the influence of right heart volume overload in children with atrial septal defect (ASD) on right ventricular outflow tract (RVOT) variables. METHODS: A prospective study was conducted in 115 children (age range: 2 days-18.1 years) with a moderate to large ASD. We determined effects of age, body length (BL), body weight (BW), and body surface area (BSA) on the variables RVOT diameter, RVOT velocity time integral (VTI), and RVOT systolic excursion (SE), and tested the predictive value of published normal values for age, BW, BL, and BSA in our ASD patients. RESULTS: In our pediatric ASD patients, the age-specific RVOT diameter (z-score: +2.2, 95% CI: 2.0-2.4, P < 0.001) was significantly increased compared to normal values with 54% of our ASD patients having a z-score >2.0. The age-specific RVOT VTI z-score (z-score: +3.6, 95% CI: 3.2-3.9, P < 0.001) was significantly increased compared to normal values with 81% of our ASD patients having a z-score >2.0. The age-specific RVOT SE z-score was not increased but slightly lower compared to normal values (z-score: -0.5, 95% CI: -0.7 to -0.3, P < 0.001) with 3% of our ASD patients having a z-score >2.0 while 12% of the patients had a z-score <-2. CONCLUSION: In our study population, we show the RVOT VTI and diameter to be relevant predictors in identifying an enlarged RVOT size and flow in children with moderate to large ASD.

Echocardiographic Reference Values for Right Atrial Size in Children with and without Atrial Septal Defects or Pulmonary Hypertension.

Right atrial (RA) size may become a very useful, easily obtainable, echocardiographic variable in patients with congenital heart disease (CHD) with right-heart dysfunction; however, according studies in children are lacking. We investigated growth-related changes of RA dimensions in healthy children. Moreover, we determined the predictive value of RA variables in both children with secundum atrial septal defect (ASD) and children with pulmonary hypertension (PH) secondary to CHD (PH-CHD). This is a prospective study in 516 healthy children, in 80 children with a secundum ASD (>7 mm superior-inferior dimension), and in 42 children with PH-CHD. We determined three RA variables, i.e., end-systolic major-axis length, end-systolic minor-axis length, and end-systolic area, stratified by age, body weight, length, and surface area. RA end-systolic length and area z scores were increased in children with ASD and PH-CHD when compared to those variables in the healthy control population. Using the Youden Index to determine the best cutoff scores in sex- and age-specific RA dimensions, we observed a sensitivity and specificity up to 94 and 91 %, respectively, in ASD children and 98 and 94 %, respectively, in PH-CHD children. We provide normal values (z scores -2 to +2) for RA size and area in a representative, large pediatric cohort. Enlarged RA variables with scores >+2 were predictive of secundum ASD and PH-CHD. Two-dimensional determination of RA size can identify enlarged RAs in the setting of high volume load (ASD) or pressure load (PH-CHD).

Serum macromolecular creatine kinase type 1 as a diagnostic clue in inflammatory bowel disease?

In adults, macromolecular creatine kinase (CK) type 1 has been linked to ulcerative colitis (UC), but not to Crohn's disease (CD). We present two patients with pediatric inflammatory bowel disease (IBD) in which macrocreatine kinase (macro-CK) type 1 led to the final diagnosis of UC. A 13 year old with bloody diarrhea and weight loss was diagnosed with CD. CK elevation was interpreted as perimyocarditis attributed to CD. CK elevation persisted; however, cardiac evaluation remained unremarkable. CK gel electrophoresis revealed macro-CK type 1. During a disease flare-up and reevaluation (endoscopy and histology), the diagnosis was changed to UC. A 12-year-old girl with bloody diarrhea, weight loss, and anemia was diagnosed with CD (patchy distal colitis and aphtoid lesions). Repeated CK elevation was observed. Gel electrophoresis confirmed macro-CK type 1. After reevaluation during a flare-up (endoscopy and histology), the diagnosis was changed to UC. Conclusion CK elevation in pediatric IBD could suggest macro-CK type 1 formation, which is possibly linked to UC. In a subset of IBD patients, macro-CK type 1 could help differentiate UC from CD.