Light Chain Cardiac Amyloidosis Presenting with Reversible Mitral and Tricuspid Regurgitation: A Case Report

Abstract Background: Light chain cardiac amyloidosis (AL-CA) is a progressive heart disease caused by the deposition of misfolded monoclonal immunoglobulin light chains. It presents as restrictive cardiomyopathy, heart failure with preserved ejection fraction, arrhythmia, atrioventricular block, proteinuria, etc. Cases with cardiac valve insufficiency as the initial main manifestation are relatively rare, and reports of reversible severe mitral and tricuspid regurgitation as the initial presentation are even scarcer. This case is worthy of reporting to enrich the clinical understanding of atypical manifestations of the disease and provide reference for early diagnosis and treatment.​ Case presentation: A 61-year-old male was admitted to our hospital in April 2022 with acute heart failure, atrial fibrillation, severe dyspnea and chest discomfort. Physical examination detected a grade 3/6 systolic murmur at the mitral area. Transthoracic echocardiography showed moderate-to-severe mitral regurgitation and moderate tricuspid regurgitation, which improved to moderate mitral and mild tricuspid regurgitation 5 days after admission, and further to mild regurgitation of both valves one month later. Conclusions: Light chain cardiac amyloidosis can present with reversible severe mitral and tricuspid regurgitation as the initial clinical manifestation, which is easy to be misdiagnosed as primary valvular heart disease. Clinicians should improve their awareness of such atypical cases. Early diagnosis and standardized treatment may help reverse valvular dysfunction and improve the prognosis of patients.