A Case of Immediate Reduction of Severe Mitral Regurgitation After the Ablation of Atrial Flutter.

Mitral regurgitation (MR) is a common valvular dysfunction often classified as primary or secondary, with the latter typically associated with left ventricular dysfunction or mitral annular dilation. A subset of MR is termed atrial functional MR, related to atrial fibrillation, but the relationship between atrial flutter and MR remains underexplored. This report describes the case of a 71-year-old man with severe MR and atrial flutter who experienced rapid improvement in MR severity following successful atrial flutter ablation and restoration of sinus rhythm. Initial echocardiography revealed severe left atrial dilation, moderate to severe eccentric MR, and moderate tricuspid regurgitation. Following ablation, MR severity significantly improved despite persistent left atrial dilation, with sustained improvement observed over two years alongside reverse remodeling of the left atrium. This case highlights the independent effect of atrial flutter on MR severity, separate from structural remodeling, and emphasizes the potential for rhythm control strategies to improve MR and avoid invasive valve interventions. It also raises important questions about the interplay between atrial arrhythmias and MR, underscoring the need for further studies to better understand atrial functional MR and its management.