Ventricular septal defect simulating patent ductus arteriosus.

The continuous machinery murmur heard over the pulmonary area is generally evidence of a patent ductus arteriosus, but there are exceptions when the murmur is due to congenital aortic septal defect (Gross, 1952; Gasul et al., 1951), to perforated aortic sinus into the right ventricle (Jones and Langley, 1949; Wood, 1950), or to rupture of an aortic aneurysm into the pulmonary artery (White et al., 1941; Porter, 1942). The case reported below with a high ventricular septal defect just below the aortic valve, complicated by aortic regurgitation from distortion ofan adjoining valve cusp, provides another example. This combination was described by Laubry and Pezzi (1921) and Laubry et al. (1933). In describing Eisenmenger's complex, Taussig (1947) stated that the aortic cusp which lies above the ventricular septal defect is often abnormally large and deep and sometimes at a lower level than the other two cusps; aortic insufficiency frequently occurs and at necropsy a scarred valve is found. The adjoining cusp may herniate into the right ventricle through the ventricular septal defect giving rise to severe aortic incompetenQe and a clinical picture resembling a patent ductus. Such cases were recorded by Allen (1941), Hurst and Schemm (1948), and Soulie et al. (1949). Ash and Murphy (1950), Ascenzi et al. (1951), and Baylis et al. (1955) recorded cases having similar clinical features where the aortic cusp had herniated through the defect into the right ventricle. Some patients in whom a high ventricular septal defect lay in such a position that the medial cusp of the aortic valve was incompletely supported, and hence collapsed from time to time giving rise to aortic insufficiency, have been noted by Gross (1953). In reporting 60 cases with isolated ventricular septal defect, Wood et al. (1954) diagnosed two more with marked aortic incompetence, one of which died suddenly and was found to have a deformed anterior aortic cusp which had partly prolapsed into the defect of the ventricular septum. Several of these authors concluded that the syndrome of ventricular septal defect with aortic incompetence is apt to be mistaken for a patent ductus and may lead to a profitless and dangerous operation.