Acute mitral regurgitation diagnosed by right-sided unilateral pulmonary edema

A 73-year-old man presented with a several-day history of hemoptysis and sudden-onset dyspnea. He had a history of hypertension and was receiving antihypertensive medication. Vital signs at presentation were temperature 36.9°C, heart rate 98 beats per minute, blood pressure 133/81 mmHg, respiratory rate 32 breaths per minute, and oxygen saturation of 91% on 12 liters per minute oxygen with a non-rebreather mask. Physical examination revealed coarse crackles in the right chest, with no audible heart murmurs. A chest X-ray showed consolidation in the right lung (Figure 1A), and chest computed tomography revealed predominant consolidation in the right lung along with dilation of the right inferior pulmonary vein (Figure 1B and C). Transthoracic echocardiography demonstrated preserved systolic function and severe mitral regurgitation with posterior leaflet prolapse (Figure 1D–G). The sputum culture was negative. Based on these findings, right-sided unilateral pulmonary edema secondary to severe mitral regurgitation was diagnosed. The patient’s respiratory status improved after initiating noninvasive positive-pressure ventilation and diuretic therapy.