35. Another patient, with mitral stenosis, showing this double density finding a bit better:
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47. (What is truncus arteriosus, you ask?) Truncus arteriosis is a complex defect where there is a single (normally there are two separate arteries) vessel arising from the heart that forms the aorta and pulmonary artery. Another congenital heart defect that occurs with truncus arteriosus is a ventricular septal defect (ventricular septum, or dividing wall between the two lower chambers of the heart known as the right and left ventricles).
48. ...and tetralogy of Fallot? Tetralogy of Fallot has four key features. A ventricular septal defect (a hole between the ventricles) and many levels of obstruction from the right ventricle to the lungs (pulmonary stenosis) are the most important. Also, the aorta (major artery from the heart to the body) lies directly over the ventricular septal defect, and the right ventricle develops thickened muscle.