Acute mitral regurgitation caused by papillary muscle rupture (PMR) is a severe complication often associated with acute myocardial infarction. A 41-year-old male developed acute mitral regurgitation due to posterior papillary muscle rupture during catheter ablation for supraventricular tachycardia. The rupture likely occurred when the chordae tendineae became entangled during catheter manipulation. The patient, a Jehovah's Witness, refused blood transfusion but accepted diluted autologous blood, a cell saver, and cardiopulmonary bypass. The ruptured posterior papillary muscle and anterior leaflet (A2) were excised, and mitral valve replacement was performed using a mechanical valve. Postoperatively, the patient recovered without mechanical circulatory support or blood transfusion and was discharged in good condition. This case highlights the rare complication of papillary muscle rupture during catheter ablation.