Spontaneous closure of muscular ventricular septal defect by growth of right ventricular muscle bundles: a rare mechanism

We present a case of an 18-year-old male with large anterior muscular ventricular septal defect. Assessment by echocardiography showed that the defect has completely closed by the growth of muscle bundles that formed a pouch-like structure on the right ventricular side. This unusual mechanism of closure has been reported in one prior case report. In our report, we present images obtained by three-dimensional echocardiography.