706 - Measurement of mitral valve end point septal separation in the pediatric emergency department using point-of-care ultrasound

Publication Number: 3683.706

Sriharsha Kambala, University of Texas Southwestern, Dallas, TX, United States; Mansi Gaitonde, University of Texas Southwestern Medical School, Dallas, TX, United States; Taketo Baba, University of Texas Southwestern/Children’s Medical Center Dallas, Dallas, TX, United States; Jo-Ann O. Nesiama, University of Texas Southwestern Medical School, Dallas, TX, United States; Bethsabee S. Stone, University of Texas Southwestern Medical School, Dallas, TX, United States

Background: End point septal separation (EPSS) is an echocardiography measurement used at the bedside to quantitatively assess left ventricular systolic ejection function (LVEF). Taken in the parasternal long axis view, it represents the distance between the anterior mitral valve leaflet and the interventricular septum in early diastole. This measurement is well-validated in adults, where EPSS greater than 0.70 cm is indicative of reduced LVEF. However, these measurements have never been validated in pediatric populations using point of care ultrasound.

Objective: This study aims to obtain EPSS measurements in a diverse pediatric population with normal cardiac function and physiology presenting to the emergency department, and to evaluate potential variation in EPSS measurements across different age groups.

Design/Methods: This was a prospective cohort pilot study with a convenience sample of one hundred pediatric patients presenting to a tertiary care pediatric emergency department. Patients were stratified into 5 age groups: 0-3 years, 3-7 years, 7-11 years, 11-15 years, 15-18 years. EPSS values among the five age groups were compared using descriptive statistics (mean, median, standard deviation, minimum and maximum values), and differences across age groups were assessed using analysis of variance.

Results: The overall mean EPSS measurement for the cohort was 0.29 cm (SD 0.12 cm; range 0.10-0.74 cm; median 0.27 cm). The mean for the 0-3 age group was 0.26 cm (SD 0.07 cm). The mean for the 3-7 age group was 0.24 cm (SD 0.12 cm). The mean for the 7-11 age group was 0.29 cm (SD 0.11 cm). The mean for the 11-15 age group was 0.32 cm (SD 0.16 cm). The mean for the 15-18 age group was 0.32 cm (SD 0.11 cm). The difference between the mean EPSS values for the age groups was not statistically significant.

Conclusion(s): The average EPSS measurement was less than 0.30 cm for this pediatric cohort, which is well below the reference threshold of 0.70 cm in adults. While there was not a statistically significant difference in the average EPSS value when patients were stratified into age groups, our findings suggest variance exists between average pediatric and adult values. The 0.70 cm threshold may not be appropriate as an EPSS standard for pediatric patients.

EPSS Measurement Example
Figure 1 - An example of the endpoint septal separation measurement obtained using M-mode with the phased array probe. Measurement of 0.36 cm obtained in the parasternal long axis view. The maximal proximity of the anterior mitral valve leaflet to the interventricular septum (E-point), and the atrial kick (A-point) can be visualized.

EPSS Measurements - Group-wise Quartile and Range Distribution
Figure 2 - A box-and-whisker plot illustrating the quartile distribution of EPSS measurements among the five age groups. The whiskers extend 1.5x the interquartile range, above and below the quartiles. Outliers are displayed as individual data points.