Anomalies associated with the parachute mitral valve: a pathologic analysis of 52 cases.

Fifty-two specimens of heart with parachute mitral valve were reviewed. An associated anomaly was present in all but two patients. In these two patients parachute mitral valve was an isolated anomaly. The associated anomalies were divided into those which form part of the developmental complex described by Shone and associates and other anomalies designated as major anomalies. Normally related great vessels were present in 35 cases, double outlet right ventricle in eight cases, complete transposition in four cases, corrected transposition and single ventricle in two cases each and straddling tricuspid valve in one case. The most common associated anomaly was an interventricular communication occurring in 37 cases. Less common anomalies were an atrial septal defect (18 cases), patent ductus arteriosus (21 cases), complete atrioventricular canal (five cases), right-sided obstructive anomalies (13 cases) and left-sided obstructive anomalies other than those as part of the Shone syndrome (11 cases).