Pulmonary edema localized in the right upper lobe accompanying mitral regurgitation.

Focal patterns of pulmonary edema are confusing and often mistaken for the more common causes of focal lung disease, pneumonia, infarction, or aspiration. The authors report four cases of right upper lobe edema secondary to mitral regurgitation. The pathogenesis believed to be responsible for this condition is the vector of blood flow from the left ventricle to left atrium, which may be targeted at the right superior pulmonary vein, locally accentuating the forces for edema formation in the right upper lobe. Pulmonary edema accompanying mitral regurgitation should be suspected whenever right upper lobe consolidation develops in a patient with known or suspected mitral valve disease. The presence of interstitial edema in the remainder of the lungs can help in the differentiation of this condition from pneumonia and other disorders.