Communication between the pulmonary and systemic circulations.

Communications between the pulmonary and systemic circulation occur normally and also in association with a number of pathological entities. On the basis of recent experience I believe that this phenomenon occurs more frequently than has previously been appreciated and may assume significant clinical importance in many cases. This report reviews the spectrum of the phenomenon of systemic-pulmonary vascular connection, particularly with regard to its occurrence and recognition in the adult age group. A number of illustrative cases are reported and the pertinent literature is reviewed.