Combined cardiac anomalies in Noonan syndrome: A case report


H S NS, S S, Patil R, Jadhav S, M C Y, Reddy B, Kharge J, Raghu TR, Shankar S, Raj S, N C, M N, Manjunath CN.Int J Surg Case Rep. 2020 May 30;72:32-36. doi: 10.1016/j.ijscr.2020.05.048. Online ahead of print.PMID: 32506025 Free PMC article.



Introduction: Noonan syndrome is the second most common syndromic cause of congenital heart disease. Most patients have an autosomal dominant inheritance, but some cases may be sporadic. Pulmonary stenosis is the most common cardiac manifestation in Noonan syndrome, associated with the atrial septal defect and hypertrophic cardiomyopathy. A combination of these three is present only in 5% of patients.

Presentation of case: We report a case of a 21-year-old female who presented to our hospital concomitant cardiac lesions associated with pulmonary stenosis, atrial septal defect, and hypertrophic cardiomyopathy. This combination of cardiac defects is an infrequent manifestation of Noonan syndrome. The patient presented with complaints of exertion syncope over the past two years. 2D-Echocardiography showed biventricular hypertrophy, dysplastic pulmonary valve, severe pulmonary stenosis, asymmetric septal hypertrophy and large atrial septal defect. The genetic analysis report showed autosomal dominant inheritance with Ras/MAPK (mitogen-activated protein kinase) Positive.

Discussion: Due to the wide spectrum of symptoms and presentations in Noonan cases, accurate clinical and genetic diagnosis, and comprehensive management of the disorder are strongly recommended.

Conclusion: We have described a case of rare combination of cardiovascular defects in Noonan Syndrome with a view to achieve better insight into the disease course and advantages of timely treatment and follow up. Our patient is currently in follow-up after treatment with percutaneous balloon pulmonary valvuloplasty, has improved symptoms, and is awaiting heart transplant.


Fig. 1 A: 2D-Echocardiography parasternal long axis showing biventricular hypertrophy. B: 2D-Echocardiography apical four-chamber showing biventricular hypertrophy, Large ASD (arrow), and color Doppler showing left to right shunt. C: 2D-Echocardiography parasternal short axis showing, dysplastic pulmonary valve (arrow), and severe pulmonary stenosis. D: 2D-Echocardiography showing LV gradient of 64.7 mm and peak pulmonary gradient of 149 mm. E: 2D and 3D-Echocardiography left parasternal long axis showing biventricular hypertrophy.


Fig. 2 A: Still capture of the cine three-chamber view showing asymmetrical septal hypertrophy (blue star), the systolic anterior motion of the mitral valve (yellow arrow), left ventricular outflow tract flow acceleration (green arrow) and mitral regurgitation (red arrow). B: Still capture of cine short-axis view at the level of the mid ventricle in diastole showing asymmetrical septal hypertrophy (blue star) along with hypertrophy of the inferior and free of the wall of the RV (green stars). C: Still capture of the cine four-chamber view showing biventricular hypertrophy (green and blue stars). D: Still capture of the axial cine sequence showing the large ostiumsecundum atrial septal defect (purple line). E: Myocardial delayed enhancement sequence in the four-chamber view showing a mid-wall scar in the basal inferoseptal segment extending to the RV side of the septum. F: Myocardial delayed enhancement sequence in the short axis view showing mid-wall scar in the basal inferoseptal segment (white arrows) and the inferior RV wall (green arrow).

Fig. 3 A: Still capture of cine sequence in systole of the right ventricular outflow tract showing sub-pulmonic/infundibular resting flow acceleration (blue arrows). B: Still capture of the cine sequence in diastole of the right ventricular outflow tract showing pulmonary regurgitation (red arrow). The level of the pulmonary annulus appreciated (green arrow).

Fig. 4 Pulmonary Balloon Valvuloplasty.