Pediatric Heart Disease

1334314 - Magnetic resonance imaging in Noonan syndrome: Case Series of Young Children

Wednesday, January 25, 2023

Location: E-POSTER

Presenting Author(s)

WY

Wenjing Yang

PhD
Fuwai hospital, China (People's Republic)

Primary Author(s)

YW

Yining Wang, MD

Dr
Fuwai Hospital, State Key Laboratory Of Cardiovascular Disease，National Center For Cardiovascular Diseases, Beijing, China (People's Republic)

Co-Author(s)

ML

Minjie Lu, MD, PhD

PhD
Fuwai Hospital, State Key Laboratory Of Cardiovascular Disease，National Center For Cardiovascular Diseases, Beijing, China (People's Republic)

Background: Noonan syndrome (NS) is an autosomal dominant disorder characterized by distinctive facial dysmorphology, short stature and a wide spectrum of cardiac abnormalities. Due to the phenotype variability makes identification of NS difficult, it is essential that the condition be identified and managed comprehensively. Our study aimed to evaluate detailed cardiac features of NS by magnetic resonance imaging (MRI).

Methods: From September 2020 to August 2021, ten small children aged in 4 months to 6 years with cardiac MRI and genetically confirmed with NS were enrolled. The cardiac function and structure characteristics, late gadolinium enhancement (LGE), T1mapping and myocardial strain were comprehensively evaluated by MRI.

Results:

Of the 10 children, 7(70%) were females and the median age is 2.9 years ranging from 0.3-6years. PTPN11 mutation was confirmed in 7 patients followed by RAF1 and LZTR1. Pulmonary stenosis(PS) presented in 5 patients (50%), and affected individuals in our cohort had a high prevalence of biventricular hypertrophy and obstruction to the outflow of both ventricles. Characteristic LGE pattern, subendocardial LGE in the anterior and anterolateral wall, and elevated of native T1 and extracellular volume (1287.8ms and 31.1%, respectively) were detected by cardiac MRI. The global peak systolic radial, circumferential, longitudinal strain (mean, 24.39%; -14.43%; -7.80%, respectively) and peak early systolic and diastolic strain rates of LV were all impaired in NS.

Conclusion: In NS, characteristic LGE pattern, together with functional and morphological imaging showing PS and biventricular hypertrophy, are helpful for diagnosis. Interstitial fibrosis confirmed by evaluated ECV and impaired myocardial deformation were also identified in NS, which may contribute to risk stratification and prognosis in NS.