Common Indications and Clinical Utility of Overnight Transthoracic Echocardiograms Performed by Pediatric Cardiology Fellows

Background: Transthoracic echocardiograms (TTEs) are used to evaluate cardiac anatomy, physiology, and function. Pediatric cardiology fellows learn to perform and interpret TTEs as part of their training, including overnight in hospitalized patients when indications are frequently urgent. The aims of this study were to evaluate the most common indications for overnight TTEs and to determine the impact of the overnight TTEs in guiding clinical management.

Methods: Retrospective chart review was completed on patients with overnight TTEs performed by in-house pediatric cardiology fellows over 13 months at a free-standing, academic children’s hospital with a mid-size cardiac surgical program. Data obtained included patient age, presence of underlying heart disease, indication for TTE, ordering hospital unit, and clinical utility of overnight TTE as based on documentation in the medical record of how the TTE aided patient care.

Results: There were 225 overnight TTEs performed on 186 patients with a median age of 5 months (0-26 years), and 55% (n=103) had known heart disease. The most common indication was evaluation of left ventricular (LV) function (40%, n=90), followed by clinical concern for undiagnosed congenital heart disease (CHD) (12.4%, n=28), evaluation for post-cardiac procedure complications (11.6%, n=26), and first TTE after birth for an infant with prenatally diagnosed CHD (9.3%, n=21) (Figure 1). The Heart Center, comprised of cardiac intensive care and step-down units, was the most common ordering location where 40% (n=90) of overnight TTEs were performed, followed by the neonatal intensive care unit (26%, n=59), pediatric intensive care unit (24%, n= 55), emergency department (9%, n=20) and general ward ( <1%, n=1). Medical decision-making based on overnight TTE results was documented for 54% of studies. Clinical utility of overnight TTE was highest for assessment of patency of the ductus arteriosus or aortopulmonary shunt in patients with CHD, with 100% documentation of TTE results guiding management compared to only 48% of TTEs performed to assess LV function, and 10% of TTEs performed on patients on extracorporeal membrane oxygenation (ECMO) support (Figure 2). Clinical utility of overnight TTE was higher in patients with known heart disease compared to those without (67% vs 44%, p=0.003).

Conclusion: The most common indication in pediatric patients for overnight TTEs was evaluation of LV function, however the TTE was noted to affect clinical management in less than half of these cases. The highest yield of TTEs documented to affect patient care were those performed in patients with known heart disease, especially those with ductal- or aortopulmonary shunt-dependent blood flow. Echocardiographic training for pediatric cardiology fellows should focus on these common and high-yield indications to prepare them for performing and interpreting overnight TTEs. Furthermore, these findings may help inform the development of appropriate use criteria for overnight TTEs in pediatric patients.