This 76-year-old female patient was referred to us for persistent heart failure symptoms in New York Heart Association [NYHA] class III to IV and severe functional mitral regurgitation (FMR) despite optimal therapeutic management combining medication, previous biventricular implantable cardioverter-defibrillator (ICD) (cardiac resynchronization therapy defibrillator [CRT-D]) implant, and atrioventricular node ablation for competing atrial fibrillation rhythm. Four months previously a CRT-D device was implanted based on conventional class I indication—drug-refractory symptomatic heart failure (NYHA class III to IV) because of postactinic cardiomyopathy (the patient had previously received radiotherapy for non-Hodgkin lymphoma) with severe left ventricular systolic dysfunction (left ventricular ejection fraction [LVEF], 29%); the electrocardiogram (ECG) showed significant ventricular conduction delay with complete left bundle branch block and 130-msec QRS complex duration. Atrial fibrillation was the underlying atrial rhythm. Besides severe left ventricular dysfunction, the transthoracic echocardiogram performed before CRT-D device implant showed a mildly dilated left ventricle (end-diastolic voume 186 mL and end-systolic volume 132 mL) and severe functional mitral regurgitation determined by failed coaptation of mitral valve leaflets resulting from symmetric dilation of the mitral anulus. Shortly after CRT-D implant, the patient underwent catheter ablation of the atrioventricular node as a result of recurring high ventricular rate atrial fibrillation.

The patient was taking acenocoumerol 1 mg adjusted to international normalized ratio value, captopril 10 mg daily, carvedilol 12.5 mg daily, spironolactone 50 mg daily, torsemide 20 mg adjusted according to weight, and metolazone 2.5 mg daily if body weight greater than 50 kg.

The patient was unable to walk up a single flight of 12 steps without stopping because of breathlessness (NYHA class III to IV) and unable to perform the 6-Minute Walk Test.