Congenital defects of the heart or arteries and valvular malformations predispose to acute bacterial inflammatory processes. It is well known that an area of fibrosis resulting either from a congenital anomaly or from a healed rheumatic infection may become the site of a subsequent bacterial inflammation. Many observers have pointed out the importance of mechanical strain resulting from the impingement of anomalous currents on the endocardium in producing foci susceptible to bacterial implantation. The numerous instances reported in the literature that have been collected and analyzed by Abbott1 support such a relationship.
In the present communication we wish to report an instance of subacute bacterial endarteritis (streptococcus viridans) of the pulmonary artery and ductus arteriosus associated with patent ductus arteriosus and pulmonic stenosis, in which the valves showed no inflammatory changes. This, to our knowledge, is the first instance on record of the association of pulmonic stenosis with patent