Severe mitral regurgitation due to right ventricular apical pacing.

A 75-year-old man with history of paroxysmal atrial fibrillation developed acute pulmonary oedema immediately after permanent pacemaker insertion for symptomatic bradycardia and was transferred to our institution. Echocardiography prior to pacemaker insertion showed normal left ventricle (LV) function and mild mitral regurgitation (MR). A single-chamber pacemaker had been inserted with the ventricular lead positioned in the right ventricular apex. He was treated with diuretics with symptomatic improvement. Investigations failed to reveal a cause for cardiac failure. Patient subsequently had multiple readmissions for heart failure and echocardiography revealed severe MR. Patient was referred for mitral valve (MV) surgery. Intraoperatively, when patient was in sinus rhythm and not paced, transoesophageal echocardiogram showed a significant reduction in the severity of MR. MV surgery was aborted and further echocardiographic characterisation revealed worsening of MR during ventricular pacing. The device was upgraded to a dual-chamber system and programmed to atrial pacing with intrinsic ventricular rhythm. He has had no further admissions over the following year.