Pulmonary edema is the most common complication of acute left ventricular heart failure. Macroscopically, the edematous lungs are heavy, cohesive, and enlarged, releasing large amounts of foamy, clear fluid upon sectioning. Microscopically, copious amounts of fluid, usually devoid of cellular components, are found in the alveoli, alveolar ducts, and bronchioles. The capillaries are dilated and filled with blood.