Two cases of severe mitral regurgitation and pulmonary hypertension
immediately after birth are presented. Initial echocardiographic
findings showed a thick atrial septum rather than a normal flap septum.
The patients were tentatively diagnosed with premature restriction of
the foramen ovale and congenital mitral regurgitation. Subsequently, the
mitral regurgitation resolved over time with improvement of pulmonary
hypertension. The postnatal ductus arteriosus closure process was
considered to be the cause of the mitral regurgitation and pulmonary
hypertension.