A 57-year-old woman with a history of persistent atrial fibrillation (AF) and known situs inversus was hospitalized in our cardiology clinic with high ventricular rate AF. The patient had a history of cardioversion (CV) many times. Cryoablation was planned after rhythm control with electrical CV when the patient was unstable. Before cryoablation, transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) were performed, and a secundum atrial septal defect (ASD) was diagnosed (Figure 1). There was no thrombus in the left atrium and the left atrial appendage, so percutaneous ASD closure was also planned. We obtained a mirror image by changing the setting of the angiographic system (HFP – Head First Prone mode). We then reached the left atrium with a transseptal sheath by passing through the ASD. After successful cryoablation (Arctic Front Advance™, Medtronic) of the pulmonary veins, the operation ended without complication (Figure 2). In another session, the ASD closure process was performed with the guidance of TEE under sedation. The defect was closed with a 17-mm Amplatzer™ Septal Occluder device (Abbott) (Figure 3). After the intervention, the patient remained in sinus rhythm and symptom-free. The patient was discharged with oral anticoagulation, amiodarone, and metoprolol.

Although most patients with ASD remain asymptomatic for many years, it can cause many situations, like an increase in end-diastolic pressure, an increase in pulmonary arterial pressure, right heart failure, thromboembolism, and atrial arrhythmia.¹² Atrial arrhythmias like AF are associated with significant morbidities in patients with ASD. It may increase the risk of stroke and 2- to 3-fold increased risk of congestive heart failure in ASD patients. Atrial arrhythmias have also been related to significant pulmonary regurgitation, indicating the need for timely intervention to preserve right ventricular function.³⁴ These findings show the importance of ASD closure in AF patients. The mirror image allows the physician to work more comfortably without the need to change the patient's position in patients with dextrocardia. Clinicians should keep in mind a mirror image approach in these patients.