The normal septal development requires a proper alignment and fusion of the two interatrial septums i.e. septum primum and septum secundum. Failure to do so may lead to a patent fossa ovalis and the development of<unk>  septal defects (ASDs).<unk>  septal defects are classified into various types based on their location and the nature of the embryological defect. The types of<unk>  septal defects that can occur are:  ostium primum,  ostium secundum,  sinus venosus,  common or single atrium and coronary sinus defects. Patent foramen ovale, commonly associated with<unk>  septal defects, is a sister condition involving communication between the two<unk>   Patent foramen ovale is not a true<unk>  septal defect as flap like tissue that functions usually like a one way valve is present in a PFO.
Atrial septal defect classification
Ventricular septal defect classification
Patent ductus arteriosus classification
Left ventricular aneurysm classification
Tricuspid stenosis classification
Pulmonic regurgitation classification
Tricuspid regurgitation classification
Mitral regurgitation classification