Interatrial right-to-left shunting developing after pulmonary resection in the absence of elevated right-sided heart pressures. Review of the literature.

Considering the literature, a symptomatic right-to-left (R-L) shunt through a persistent foramen ovale (PFO), developing after a pulmonary resection, can occur without elevated right-sided heart pressures, but its frequency seems to be very low. However, considering the high frequency of a PFO in the normal population (20 percent) and the high frequency of pulmonary resections carried out today, it might be possible that this kind of complication is occurring more frequently, possibly in a more "benign" form, in which it is more difficult to recognize, especially if one is unaware of the possibility of this kind of complication. This R-L shunt seems to occur more frequently after a right-sided pneumonectomy. Important clinical clues suggestive for this complication are as follows: first, a relatively symptomless interval of a few months between the operation and the onset of symptoms; second, the posture dependency of the dyspnea, ie, the dyspnea becoming worse in the upright position (platypnea); and third, the volume dependency of the R-L shunt, ie, the shunt becoming worse in a dehydrated state.