Unilateral pulmonary edema secondary to left heart failure.

A 56-year-old man with a failing aortic prothesis involving aortic insufficiency and with a dissecting aneurysm of the aortic cross, developed a unilateral pulmonary edema. Although radiological literature often describes this phenomenon, it is sometimes mis-diagnosed in medical clinics. The literature available is briefly reviewed and we discuss the most probable mechanisms causing unilateral presentation of pulmonary edema. The effect of gravity or posture, with or without variations of pulmonary venous pressure, disturbances of the neurogenic control of capillary size and permeability, pleural pathologies and impairment of vascularization of one lung are hypotheses put forward to explain the unilaterality of the distribution.