Search results
Results From The WOW.Com Content Network
Atrial septal defect (ASD) is a congenital heart defect in which blood flows between the atria (upper chambers) of the heart.Some flow is a normal condition both pre-birth and immediately post-birth via the foramen ovale; however, when this does not naturally close after birth it is referred to as a patent (open) foramen ovale (PFO).
The left and right sides of the heart are named from a dorsal view, i.e., looking at the heart from the back or from the perspective of the person whose heart it is. There are four chambers in a heart: an atrium (upper) and a ventricle (lower) on both the left and right sides. [1] In mammals and birds, blood from the body goes to the right side ...
right heart pressure is higher than left heart pressure and/or the shunt has a one-way valvular opening. Small physiological, or "normal", shunts are seen due to the return of bronchial artery blood and coronary blood through the Thebesian veins , which are deoxygenated, to the left side of the heart.
Sketch showing foramen ovale in a fetal heart. Red arrow shows blood from the inferior cava traveling to the right atrium and then to the left atrium. HF: right atrium, VF: left atrium. HH and VH: right and left ventricle. The heart still has a common pulmonary vein (LV), instead of four.
These routes include moving through a patent foramen ovale (a congenital hole connecting the right and left atria of the heart), a ventricular septal defect (a congenital hole connecting the ventricles), or a pulmonary arteriovenous fistula, where arteries in the lungs connect directly to veins without capillaries in between.
It increases pressure on the left side of the heart, decreasing the right to left shunt. The decreased shunt volume results in a decrease in deoxygenated blood flow entering the systemic circulation and an increase in deoxygenated blood flow antegrade through the obstructed right ventricular outflow tract.
Classic for a patent foramen ovale (PFO) or atrial septal defect (ASD). A PFO is lack of closure of the foramen ovale. At first, this produces a left-to-right heart shunt. This does not produce cyanosis, but causes pulmonary hypertension. Longstanding uncorrected atrial septal defects can also result in Eisenmenger syndrome.
With enough pressure, blood may travel from the right atrium to the left. If there is a clot in the right side of the heart, it can cross the PFO, enter the left atrium, and travel out of the heart and to the brain, causing a stroke. If the clot travels into a coronary artery it can cause a heart attack. [6]