Abstract:

Objective

To investigate the utility of contrast transthoracic echocardiography（cTTE） in the assessment of right-to-left shunt （RLS）-related diseases in pediatric patients， aiming to establish standardized guidelines for its application in pediatrics.

Methods

From January 2022 to December 2023，the clinical data and cTTE results of 350 pediatric patients suspected of having RLS-related diseases and who underwent cTTE at the Children's Hospital， Zhejiang University School of Medicine were retrospectively collected. The clinical manifestations and cTTE evaluation results for different RLS-associated conditions，as well as adverse reactions of cTTE， were analyzed.

Results

A cohort of 350 pediatric patients underwent cTTE examination， comprising 189 males and 161 females， with a mean age of （10.20±2.92） years. The overall positivity rate was determined to be 70.86% （248/350）. A total of 257 children were clinically diagnosed with patent foramen ovale （PFO）. Among them， 16 cases （16/257， 6.23%） had negative cTTE results， 59 （59/257， 22.96%） had grade I shunt， 113 （113/257， 43.97%） had grade Ⅱ shunt， and 69 （69/257，26.85%） had grade Ⅲ shunt. Fifty PFO patients underwent percutaneous closure of patent foramen ovale.Using transesophageal echocardiography （TEE） as the gold standard， the sensitivity of cTTE for diagnosing PFO was 96% （48/50）. There were 7 cases of extracardiac pulmonary shunt， including 5 cases of pulmonary arteriovenous fistula （4 cases of grade Ⅲ shunt and 1 case of grade Ⅱ shunt） and 2 cases of Abernethy malformation with hepatopulmonary syndrome （1 case of grade Ⅲ shunt and 1 case of grade Ⅱ shunt）. There were 7 cases of extracardiac pulmonary shunt， including 5 cases of pulmonary arteriovenous fistula （4 cases of grade Ⅲ shunt and 1 case of grade Ⅱ shunt） and 2 cases of Abernethy malformation with hepatopulmonary syndrome （1 case of grade Ⅲ shunt and 1 case of grade Ⅱ shunt）. A total of 4 cases （4/350， 1.14%） had different degrees of adverse reactions after cTTE examination， mainly cough and mild dyspnea， which were relieved after oxygen inhalation and drug treatment.

Conclusion

cTTE has important value for clinical diagnosis and quantitative evaluation of RLS of different intracardiac and extracardiac causes in children， and holds promise for application in the field of pediatrics.

Key words: Contrast transthoracic echocardiography, Children, Patent foramen ovale, Pulmonary arteriovenous fistula, Right-to-left shunt