The SI unit for pressure is the pascal (Pa), equal to one newton per square metre (N/m 2 or kgÂ·m â1 Â·s â2). This name for the unit was added in 1971; before that, pressure in SI was expressed simply in newtons per square metre.
A leaking mitral valve allows blood to flow in two directions during the contraction. Some blood flows from the ventricle through the aortic valve â as it should â and some blood flows back into the atrium. A leaking (or regurgitant) aortic valve allows blood to flow in two directions.
Watch an animation of mitral valve regurgitation. A leaking mitral valve allows blood to flow in two directions during the contraction. Some blood flows from the ventricle through the aortic valve â as it should â and some blood flows back into the atrium.