Hemodynamic deterioration because of worsening of mitral regurgitation can occur in a small number of patients undergoing atrioventricular node (AVN) ablation and pacing therapy. Patients with moderate mitral regurgitation before ablation seem prone to this complication. Successful permanent His-bundle pacing after AVN ablation was performed in a patient with chronic atrial fibrillation and moderate mitral regurgitation. Pulmonary capillary wedge pressure V-wave amplitude was markedly diminished and the mitral regurgitation area, calculated from the echocardiogram, was decreased by His-bundle pacing compared with that during right ventricular outflow tract or apical pacing.