Age-Related Changes in Inferior Vena Cava Dimensions among Children and Adolescents with Syncope

Echocardiographic estimation of pulmonary arterial and right atrial pressures in children with congenital heart disease: a comprehensive prospective study and introduction of novel equations

BACKGROUND

Pediatric pulmonary hypertension (PH) is characterized by a mean pulmonary arterial pressure exceeding 20 mmHg. There is limited research on the suitability of adult-based methods for estimating PH in pediatric populations. Using established formulas for adults, this study aimed to evaluate the correlation between echocardiographic estimates of systolic, diastolic, and mean pulmonary arterial pressures, and mean right atrial pressures in children with congenital heart disease (CHD).

METHODS

A prospective study was conducted involving children with CHD undergoing cardiac catheterization without prior cardiac surgery. We used echocardiography to estimate pulmonary and right atrial pressures and compared these with invasively measured values. Four reliable regression equations were developed to estimate systolic, diastolic, and mean pulmonary arterial pressures, and mean right atrial pressures. Cutoff values were determined to predict the occurrence of PH. Linear regression, Bland-Altman analysis, and receiver operating characteristic curve analysis were performed to assess the accuracy of echocardiography and establish diagnostic thresholds for PH.

RESULTS

The study involved 55 children (23 with normal pulmonary arterial pressure and 32 with PH) with acyanotic CHD aged 1 to 192 months. Four equations were developed to detect high pulmonary arterial pressures, with cutoff values of 32.9 for systolic pulmonary arterial pressure, 14.95 for diastolic pulmonary arterial pressure, and 20.7 for mean pulmonary arterial pressure. The results showed high sensitivity and moderate specificity but a tendency to underestimate systolic and mean pulmonary arterial pressures at higher pressures.

CONCLUSIONS

The study provides valuable insights into the use of adult-based echocardiographic formulas for estimating PH in pediatric patients with acyanotic CHD.

Relationship between syncopal symptoms and head-up tilt test modes

OBJECTIVE

Head-up tilt test (HUTT) is an important tool in the diagnosis of pediatric vasovagal syncope. This research will explore the relationship between syncopal symptoms and HUTT modes in pediatric vasovagal syncope.

METHODS

A retrospective analysis was performed on the clinical data of 2513 children aged 3-18 years, who were diagnosed with vasovagal syncope, from Jan. 2001 to Dec. 2021 due to unexplained syncope or pre-syncope. The average age was 11.76 ± 2.83 years, including 1124 males and 1389 females. The patients were divided into the basic head-up tilt test (BHUT) group (596 patients) and the sublingual nitroglycerine head-up tilt test (SNHUT) group (1917 patients) according to the mode of positive HUTT at the time of confirmed pediatric vasovagal syncope.

RESULTS

(1) Baseline characteristics: Age, height, weight, heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and composition ratio of syncope at baseline status were higher in the BHUT group than in the SNHUT group (all P < 0.05). (2) Univariate analysis: Age, height, weight, HR, SBP, DBP, and syncope were potential risk factors for BHUT positive (all P < 0.05). (3) Multivariate analysis: syncope was an independent risk factor for BHUT positive, with a probability increase of 121% compared to pre-syncope (P<0.001).

CONCLUSION

The probability of BHUT positivity was significantly higher than SNHUT in pediatric vasovagal syncope with previous syncopal episodes.

The relationship between demographic factors and syncopal symptom in pediatric vasovagal syncope

This research proposed to retrospectively analyze 20 years of clinical data and investigate the relationship between demographic factors and syncopal symptom in pediatric vasovagal syncope. A total of 2513 children, 1124 males and 1389 females, age range 3-18 years, who presented to Department of Pediatric Cardiovasology, Children's Medical Center, The Second Xiangya Hospital, Central South University with unexplained syncope or pre-syncope and were diagnosed with vasovagal syncope were retrospectively collected and divided into syncope group (n = 1262) and pre-syncope group (n = 1251). (1) Females had a 36% increased risk of syncope compared to males, a 27% increased risk of syncope for every 1-year increase in age, and a 2% decreased risk of syncope for every 1 cm increase in height. (2) A non-linear relationship between age, height, weight and syncope was observed. When age > 10.67 years, the risk of syncope increases by 45% for each 1-year increase in age; when height < 146 cm, the risk of syncope decreases by 4% for each 1 cm increase in height; when weight < 28.5 kg, the risk of syncope decreases by 10% for each 1 kg increase in weight. Demographic factors are strongly associated with syncopal symptom in pediatric vasovagal syncope and can help to predict the risk.