Utility of transesophageal echocardiography for intra-operatively assessing pulmonary artery pressure across an isolated ventricular septal defect in children.

Background: The magnitude of pulmonary hypertension (PH) is extremely important with respect to the intra-operative management of children and infants with an isolated ventricular septal defect (VSD). This study aimed to assess the feasibility and accuracy of transesophageal echocardiography for estimating pulmonary arterial systolic pressure (PASP) across isolated VSD.

Methods: We compared the results of transesophageal echocardiography vs invasive PASP measured simultaneously. This study included 40 patients (age: 6 months to 6 years; weight: >5 kg) who were undergoing elective surgery for isolated VSDs. Flow signals across the VSDs were identified as high velocity turbulent signals in systole via continuous wave Doppler at 0-120° at the mid-esophageal level. Peak velocities were recorded. Radial artery systolic pressures were assessed invasively, and PASPs were obtained after exposing the pulmonary artery intra-operatively.

Results: After excluding five patients because of unusable measurements, invasive PASP measurements were obtained in 35 patients (87.5%). There were no significant biases between echocardiographic and catheterization measurements of PASP, with a tight confidence interval measuring, on average, up to 2.6 mmHg. However, the ± 2 standard deviation limits of agreement for mean PASP were -3.8 and 10.6 mmHg.

Conclusion: PASP measurements via transesophageal echocardiography in cardiac surgical patients under general anesthesia are recommended for use as a screening and monitoring tool for PH in children and infants, but cannot be used as a diagnostic tool.