Thyrotoxicosis-Induced Chordal Rupture Causing Severe Mitral Regurgitation: Surgical Management and Outpatient...

Thyrotoxicosis often causes tachyarrhythmias and high-output states but rarely results in structural valvular failure.

A 57-year-old man with new-onset thyrotoxicosis presented with atrial fibrillation and torrential mitral regurgitation from a flail anterior leaflet from chordal rupture. After stabilization with methimazole and β-blockade, he underwent mitral valve replacement with a 33-mm porcine bioprosthesis, as extensive leaflet and chordal damage precluded durable repair. Postoperatively, transient left ventricular dysfunction improved with medical therapy. Sinus rhythm was maintained on downtitrated amiodarone, and anticoagulation with apixaban was selected after shared decision-making for atrial fibrillation management.

This case underscores the structural impact of thyrotoxicosis on valvular tissue, through hyperdynamic stress and matrix remodeling. Preoperative endocrine optimization and intraoperative storm prevention are critical.

Thyrotoxicosis can cause chordal rupture and flail leaflet. Repair is preferred, but replacement is appropriate when repair is not durable. Management requires endocrine-cardiac coordination and individualized antithrombotic therapy. Expect early ejection-fraction decline after surgical correction.