Treat-and-repair strategy for atrial septal defect with left ventricular systolic dysfunction: a case report of cardiac resynchronization therapy responder.

Background: The treatment strategy for closing atrial septal defect (ASD) in patients with left ventricular (LV) dysfunction remains to be elucidated. Current guidelines recommend a balloon occlusion test to determine whether the ASD should be closed, fenestrated, or not. Case summary: A 56-year-old man was referred to our hospital for secundum ASD with LV dysfunction. He was diagnosed with non-ischaemic cardiomyopathy with LV ejection fraction of 24%. A secundum ASD with a diameter of 18 mm also existed, with a pulmonary blood flow to systemic blood flow ratio over 2.0. Initially, ASD closure was deemed challenging because the occlusion test resulted in abrupt elevation of the left atrial pressure. The patient had been implanted cardiac resynchronization therapy (CRT) with a defibrillator for a left bundle branch block by the referring physician; however, the LV lead was positioned at the anterior interventricular vein. Since he was a non-responder for CRT, the LV lead was repositioned to the left posterior vein at our hospital. The patient's haemodynamic status improved after CRT optimization and medical therapy. Eventually, repeated occlusion tests allowed for successful transcatheter ASD closure. Discussion: This case demonstrates a novel treat-and-repair strategy for patients with ASD and LV systolic dysfunction. Although initial evaluation precluded ASD closure, CRT optimization and medical therapy for heart failure improved the haemodynamic status and facilitated ASD closure.