A 4-year-old boy, diagnosed at 4 months of age with a restrictive perimembranous ventricular septal defect (VSD) and lost to follow-up, was referred for recurrent episodes of exertional syncope that had been occurring for several months.
The physical examination is normal except for a strong systolic ejection murmur over the pulmonary region.
The ECG shows a deviation of the right QRS axis with exclusive R waves on the right precordial leads.
The echocardiogram shows these features on the parasternal short axis slice (video 1) and on the right wide axis exit slice. What is your diagnosis?