Successful recovery from refractory hypoxia due to right-to-left shunting associated with iatrogenic atrial septal defect after catheter ablation in a patient with a left-ventricular assist device: a case report

Background Catheter ablation (CA) has been reported to be an effective therapeutic option for ventricular arrhythmias, even in patients with a left-ventricular assist device (LVAD). However, the issues of right-to-left shunting due to iatrogenic atrial septal defect (iASD) associated with procedures for CA have not been well documented. We describe a rare case of refractory hypoxia associated with right-to-left shunting via iASD after CA through the transseptal approach in an LVAD patient. Case summary A 52-year-old Asian man with a continuous-flow implantable LVAD and progressive right ventricular (RV) dysfunction was admitted because of refractory ventricular tachycardia (VT) and subsequent right heart failure. Since VT could not be controlled by intravenous administration of multiple antiarrhythmic drugs, VT ablation via the transseptal approach was performed. Ventricular tachycardia was terminated to the sinus rhythm after VT ablation; however, hypoxia associated with significant right-to-left shunting across the iASD was detected. Intensive medical management, such as an adjusted mechanical ventilator to increase pulmonary vascular compliance and adjustment of LVAD pump speed, as well as the use of intravenous inotropes to support impaired RV function successfully stabilized the haemodynamic and improved hypoxia for the disappearance of right-to-left shunting. Echocardiography at 7 months after CA showed that the significant iASD and right-to-left shunting had disappeared. Discussion The evaluation of RV function prior to VT ablation via the transseptal approach is important in the postoperative management of patients with LVAD, because RV dysfunction may cause refractory hypoxia due to iASD.