Successful Bailout of Noonan Syndrome with Obstructive Hypertrophic Cardiomyopathy During Percutaneous Intramyocardial Septal Radiofrequency Ablation

Background: Cardiac disorders such as hypertrophic cardiomyopathy (HCM) are common in patients with Noonan syndrome (NS). Some patients can develop heart failure associated with HCM, and the long-term outcome of patients with NS with HCM is reported to be worse. Case presentation: We report three patients diagnosed with NS. We initially thought that three patients were diagnosed with only HCM. Three patients' facial features were concealed, making it difficult for us to make a differential diagnosis of NS. Finally, genetic testing identified three patients as NS with HCM. Owing to these patients’ conditions, medical treatment was not effective. Patients were treated with percutaneous intramyocardial septal radiofrequency ablation (PIMSRA). Three patients recovered well, and there was no complication. Conclusions: We describe 3 patients with NS and HCM treated with PIMSRA. PIMSRA is a new therapeutic tool for treating NS with HOCM that can decrease the left ventricular wall thickness, reduce wall stress, and improve cardiac function. Early identification of congenital heart abnormalities and genetic testing are important in diagnosing NS with HCM.