Anatomy Patent foramen ovale is due to- A Failure of closure of sinoatrial orifice B Failure of fusion of septum primum and endocardial cushion C Failure of fusion of septum primum and septum intermedium D Failure of fusion of septum primum and septum secondum 💡 Explanation Patent foramen ovale is due to- ✓ Correct Answer: D. Failure of fusion of septum primum and septum secondum