Unilateral Diffuse Alveolar Hemorrhage Due to Selective Directionality of Mitral Regurgitant Jet in a Patient With Severe Aortic Stenosis

Diffuse alveolar hemorrhage (DAH) in cardiac diseases results from pulmonary capillary stress failure due to pulmonary venous hypertension. The most common cardiac causes of DAH are heart failure and mitral valvular disease. Patients typically manifest with hemoptysis, radiologic chest abnormalities, and anemia. The chest infiltrates are generally bilateral, similar to pulmonary edema. Rarely, the chest infiltrates can be unilateral, mimicking an infectious etiology. We present the case of an 88-year-old female with critical aortic stenosis, who presented with shortness of breath, unilateral right lung infiltrates, and mild leukocytosis. The patient was misdiagnosed with pneumonia as pulmonary edema or DAH was expected to be a bilateral finding on chest imaging. The patient deteriorated and DAH was eventually diagnosed by bronchoscopy.