How should I treat a perimembranous interventricular defect following aortic valve replacement surgery?

BACKGROUND: A 73-year-old man was admitted to our Institute for repeated episodes of congestive heart failure. The patient was affected by arterial hypertension, dyslipidaemia, severe chronic obstructive pulmonary disease, and recurrent atrial fibrillation. Two months earlier he had undergone aortic valve replacement with a biological prosthesis for severe stenosis. Echocardiography showed a left-to-right shunt localised in the left ventricular outflow tract, normal morphology and function of the aortic valve prosthesis, and a hyperkinetic left ventricle. INVESTIGATION: Physical examination, electrocardiography, transthoracic and transoesophageal echocardiography, right heart catheterisation, left ventricular angiography. DIAGNOSIS: Post-surgical perimembranous interventricular defect with a clinically significant left-to-right shunt. MANAGEMENT: Percutaneous closure with a ventricular septal defect occluder.