Quantification of Right Atrial-Indexed End-Systolic Volumes and Emptying Fraction in Children Undergoing Cardiac Surgery With Two-Dimensional Transesophageal Echocardiography: A Prospective Observational Study.

Objectives: The primary objective of this study was to establish "normal" right atrial (RA)-indexed end-systolic volumes (ESVs) and emptying fraction (EF) in children undergoing ventricular septal defect (VSD) repair using two-dimensional (2D) transesophageal echocardiography (TEE). Secondary objectives were to obtain RA-indexed ESV and EF in children with RA/right ventricular (RV) volume overload (atrial septal defect [ASD]) and RV pressure overload (tetralogy of Fallot [TOF]) and to determine whether baseline differences existed in these indices among the three lesions.

Design: A prospective observational study.

Setting: Tertiary referral center and a university level teaching hospital.

Participants: The study comprised 90 children (30 in each cohort) >3 kg and <14 years old admitted for elective repair of either VSD, TOF, or ASD.

Measurements And Main Results: RA ESV and EF were measured in the midesophageal four-chamber view using the area-length and the modified Simpson's methods with 2D TEE in the prebypass period. Mean RA- indexed ESV (area-length method) in the VSD cohort was 24.2 ± 6.7 mL/m, whereas it was significantly greater in the TOF (31.9 ± 9.8 mL/m; p = 0.0008) and ASD (52 ± 12.9 mL/m; p < 0.0001) cohorts. RA EF in the TOF cohort was 48.4% ± 7.6%, which was significantly more than in the VSD (41.5% ± 11.8%; p = 0.0093) and ASD (39.1% ± 12.3%; p = 0.0008) cohorts.

Conclusions: This was the first study using 2D TEE to measure RA indices in children with and without right-sided heart dilation undergoing cardiac surgery. In this study, RA, ESV, and EF were considerably different in children with congenital heart disease causing RV pressure or volume overload. Additional studies can examine how these values can be used for risk stratification in this cohort of patients or how they correlate with measures of ventricular performances.