The concept of unclosed foramen ovale: During embryonic development, the primary and secondary septum fuse abnormally, leaving a crescent-shaped cleft at the top of the fossa ovalis, which is the unclosed foramen ovale. In fact, the foramen ovale is a vital channel necessary for fetal development, and it is through this channel that blood from the mother’s umbilical vein enters the left side of the fetal heart cavity and is then distributed throughout the body to provide the oxygen and nutrients needed for fetal development. At birth, with the first cry, the pressure in the left atrium rises and the oval fossa valve is pressed against the edge of the oval fossa to form a functional closure, which is usually complete anatomically until 5 to 7 months after birth. Therefore, it is possible that the foramen ovale may remain open up to one year of age, possibly with a small shunt, and even in 5%D10 % of individuals the foramen ovale remains open and unclosed throughout life, with no effect on cardiac hemodynamics. Therefore, a patent foramen ovale in infancy is a normal physiological phenomenon, not a precordial disease, and usually does not require surgery. However, if the central atrial septal defect is large, greater than 8D10 mm, with a large fractional flow, it is called a central atrial septal defect and requires surgical repair. The timing of surgery should be aimed to be done in young children 2D4 years old. Congenital heart disease with increased right atrial pressure is often combined with an unclosed foramen ovale, which often does not cause a shunt between the two interventricular chambers. Echocardiography shows an interrupted or misaligned echogenicity in the upper part of the thin film-like echo of the foramen ovale with a large marginal oscillation.