Completed atrioventricular block induced by atrial septal defect occluder unfolding: A case report

BACKGROUND: An atrial septal defect is a common condition and accounts for 25% of adult congenital heart diseases. Transcatheter occlusion is a widely used technique for the treatment of secondary aperture-type atrial septal defects (ASDs). CASE SUMMARY: A 30-year-old female patient was diagnosed with ASD by transthoracic echocardiography (TTE) 1 year ago. The electrocardiogram showed a heart rate of 88 beats per minute, normal sinus rhythm, and no change in the ST-T wave. After admission, TTE showed an atrial septal defect with a left-to-right shunt, aortic root short-axis section with an ASD diameter of 8 mm, a parasternal four-chamber section with an ASD diameter of 9 mm, and subxiphoid biatrial section with a diameter of 13 mm. Percutaneous occlusion was proposed. The intraoperative TTE scan showed that the atrial septal defect was oval in shape, was located near the root of the aorta, and had a maximum diameter of 13 mm. A 10-F sheath was placed in the right femoral vein, and a 0.035° hard guidewire was used to establish the transport track between the left pulmonary vein and the inferior vena cava. A shape-memory alloy atrial septal occluder with a waist diameter of 20 mm was placed successfully and located correctly. TTE showed that the double disk unfolded well and that the clamping of the atrial septum was smooth. Immediately after the disc was revealed, electrocardiograph monitoring showed that the ST interval of the inferior leads was prolonged, the P waves and QRS waves were separated, a junctional escape rhythm maintained the heart rate, and the blood pressure began to decrease. After removing the occluder, the elevation in the ST segment returned to normal immediately, and the sinus rhythm returned to average approximately 10 min later. After consulting the patient’s family, we finally decided to withdraw from the operation. CONCLUSION: Compression of the small coronary artery, which provides an alternative blood supply to the atrioventricular nodule during the operation, leads to the emergence of a complete atrioventricular block.