Case Report Diagnostic Management and Surgical Treatment of Isolated Tricuspid Regurgitation Arthur Cicupira Rodrigues de Assis, 1 Gustavo Andre Boeing Boros, 1 Lea Maria Macruz Ferreira Demarchi, 2 Thiago Luis Scudeler, 1 and Paulo Cury Rezende 1 1 MASS Research Unit, Instituto do Coração (InCor), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil 2 Pathology Department, Instituto do Coração (InCor), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil Correspondence should be addressed to Paulo Cury Rezende; rezendepaulo@hotmail.com Received 29 March 2021; Accepted 18 August 2021; Published 13 September 2021 Academic Editor: Dietmar Kivelitz Copyright © 2021 Arthur Cicupira Rodrigues de Assis et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Severe tricuspid regurgitation is especially caused by pulmonary hypertension. Primary tricuspid regurgitation in the absence of pulmonary hypertension and of unknown etiology is a very rare condition with scarce data about its diagnosis, treatment, and follow-up. The particularities of surgery indication and outcomes are still not clearly known. A 72-year-old woman with a medical history of coronary artery bypass grafting three years ago presented with shortness of breath and low limb edema. Physical examination revealed a prominent bilateral jugular turgescence, hepatomegaly, peripheral edema, and a left midsternal border holosystolic murmur, suggestive of tricuspid regurgitation. The echocardiogram confirmed the diagnosis and showed preserved right and left ventricular dimensions and function. Coronary angiography showed no new obstructive lesions and patent surgical grafts. Right cardiac catheterization revealed mild pulmonary hypertension and increased right atrium pressure. Cardiac magnetic resonance showed mild right ventricular dilation with normal systolic function and normal left chambers. No late gadolinium enhancement was detected. Because of persistent symptoms, even after optimization of medical therapy, the patient was submitted to tricuspid valve replacement surgery. Immediately after the surgery, the patient developed significant right ventricular dysfunction, with the need of continuous hemodynamic support. She had progressive clinical recovery that was confirmed by serial echocardiograms that showed improvement in right ventricular volume and function. The patient was discharged with no signs or symptoms of right heart failure. The histopathological examination showed significant and diffuse myxomatous degeneration of the leaflets. No signs of infection or vegetation nor disruption of strands were observed. This report illustrates a very rare case of symptomatic primary isolated severe tricuspid regurgitation caused by myxomatous degeneration of the leaflets. The thoroughly diagnostic workup is presented, and only the histopathological analysis of the leaflets revealed the etiologic process. Surgical treatment indicated before the onset of right ventricular failure was essential to patient’s full recovery. 1. Introduction The major etiology of tricuspid regurgitation (TR) is sec- ondary to pulmonary hypertension, but primary disease occurs in about 10% of the cases [1]. In this setting, congen- ital and acquired diseases should be considered, such as Ebstein’s anomaly, atrioventricular septal defects, myxoma- tous prolapse, endocarditis, rheumatic disease, carcinoid syn- dromes, and blunt trauma. Secondary TR is most related to right ventricular remodeling in pulmonary hypertension. Interestingly, atrial fibrillation (AF) may be considered the cause of tricuspid insufficiency rather than the consequence, especially when it is long lasting. In the acute setting, right ventricular infarction can result in papillary muscle damage and subsequent acute atrioventricular valvar regurgitation, although mitral valve is the most common. Hindawi Case Reports in Cardiology Volume 2021, Article ID 9928811, 5 pages https://doi.org/10.1155/2021/9928811