SESSION TITLE: Cardiothoracic Surgery SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Acute mitral valve regurgitation (AMR) occurs when there is structural compromise in components of the mitral valve. Clinical presentations may be confounded by more common cardiopulmonary processes1. This may delay diagnosis and management, thus increasing patient morbidity and mortality2. CASE PRESENTATION: An 84 YOF presents with a 6 day history of myalgias, palpitations, cough + SOB. PMH includes HTN, esophageal spasm, and DVT. Admission exam reveals tachycardia, irregularly irregular rhythm, and grade IV holosystolic murmur along the left sternal border. Bilateral (bl) rales heard in her lower lung fields. ECG confirms A-fib with RVR.WBC is 17,700, lactic acid 1.4 mmol/L, BNP 8,838 pg/mL, procalcitonin 0.46 ng/mL.Urine Streptococcal pneumoniae Ag is positive.Blood, sputum cultures + rapid influenza testing are negative. CXR shows mild cardiomegaly with bl pulmonary edema (Fig 1).Non-contrast chest CT shows bl upper lobe (UL) groundglass densities, moderate bl pleural effusions, bibasilar atelectasis, and focal areas of bl UL nodularity(Fig 2).Despite rate control + broad spectrum antibiotics, her hypoxia worsened.TTE showed EF 70%, normal ventricular sizes, PASP 50 mmHg, moderately dilated LA, myxomatous mitral thickening with a flail posterior leaflet, ruptured chordae tendinae, severe mitral regurgitation and an eccentric anterior jet penetrating the pulmonary veins.Pt is mechanically ventilated due to acute hypoxic respiratory failure + undergoes mitral valve repair.One week post-op, she is in no respiratory distress and saturating well on room air, suggesting complete reversal of her acute cardiopulmonary disease (Fig 3). DISCUSSION: Chord rupture is the most common etiology of AMR, typically affecting the thinner posterior mitral leaflets3. It is most often seen as a spontaneous event in elderly pts with no known heart disease presenting with sudden SOB and hypotension3. LA pressure rapidly increases causing pulmonary congestion + edema3. CXR findings of RUL pulmonary edema has high specificity but bl edema and effusions are more common1-3. Bl pulmonary edema is often interpreted as a manifestation of CHF or underlying infection and can delay tx of the valvular defect.CT findings in AMR include intralobar septal thickening, parabronchial cuffing and diffuse groundglass opacities1,3. CONCLUSIONS: SOB is commonly encountered in medicine.Despite evidence of infection or another common cardiopulmonary process, clinical correlation of sudden dyspnea and new murmur should prompt suspicion of AMR.CXR, CT and echo should all be utilized to evaluate AMR severity and initiate urgent surgical intervention.This case demonstrates the potential to reverse clinical symptoms and drastically improve pt outcomes. Reference #1: Brander L et al. Right-sided pulmonary oedema.Lancet 1999;354:1440. Reference #2: Morris P et al. Focal pulmonary oedema: an unusual presentation of acute mitral regurgitation.Thorax 2013;68:498. Reference #3: Lucenti M et al. Acute shortness of breath. J Emerg Med 2003;24(3):319. DISCLOSURE: The following authors have nothing to disclose: Patrick Twohig, Jaclyn Rivington, Rex Yung No Product/Research Disclosure Information