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

Introduction Catheter ablation has been reported 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 catheter ablation have not been well documented. Case Report A 52-year-old male 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. VT 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 resistance and adjustment of LVAD pump speed as well as the use of intravenous inotropes to support impaired RV function successfully stabilised the hemodynamic and improved hypoxia due to the disappearance of right-to-left shunting. Summary We described a rare case of refractory hypoxia due to significant right-to-left shunting via iASD after catheter ablation. The present case suggests that pre-existing impaired RV function may be responsible for the development of refractory right-to-left shunting after catheter ablation, and implies that evaluation of RV function prior to VT ablation via the transseptal approach is important in postoperative management in a patient with a LVAD. Catheter ablation has been reported 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 catheter ablation have not been well documented. A 52-year-old male 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. VT 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 resistance and adjustment of LVAD pump speed as well as the use of intravenous inotropes to support impaired RV function successfully stabilised the hemodynamic and improved hypoxia due to the disappearance of right-to-left shunting. We described a rare case of refractory hypoxia due to significant right-to-left shunting via iASD after catheter ablation. The present case suggests that pre-existing impaired RV function may be responsible for the development of refractory right-to-left shunting after catheter ablation, and implies that evaluation of RV function prior to VT ablation via the transseptal approach is important in postoperative management in a patient with a LVAD.