Can Patent Foramen Ovales Cause Problems?

Discussion During fetal development, the heart primum and secundum septa grow and overlap leaving a small but important channel between the two atria. The foramen ovale is a flap valve moving blood from the right atrium into the left atrium directly and bypassing the high pressure pulmonary system. After birth and breathing air, the neonate’s lungs open up and the pulmonary vascular resistance decreases. The left atrium now has a relatively higher pressure than the right atria, and therefore pressure on the flap valve closes the foramen ovale. Usually within 6-12 months, the fusion of the primum and secundum of the flap valve is complete. However, this normal change in anatomy and physiology does not occur in a significant number of people (20-34%, and decreases with time with 34% at 30 years and 20% at 80 years) and this situation is called a patent foramen ovale (PFO). Note that a PFO is an abnormality of the atrial septum but is not considered an atrial septal defect (ASD) which results from abnormal development of the atrial septum tissues. ASDs occur in about 1.6/1,000 live births, and are usually diagnosed because of cyanosis, exercise intolerance or a continuous murmur at the left upper sternal border with fixed splitting of S2. The continuous left-to-right shunting can cause volume overload and heart failure. It can also lead to emboli. PFOs are different than ASDs. They are much more common as noted, generally do not have a murmur, and usually do not cause any ...
Source: PediatricEducation.org - Category: Pediatrics Authors: Tags: Uncategorized Source Type: news