High-risk transseptal puncture in a patient with a “pancake” deformity in the left atrium caused by descending aorta displacement

Catheter ablation via the transseptal approach has recently become a widely performed technique for treating atrial fibrillation (AF). However, fluoroscopic imaging provides limited anatomic guidance for the left atrial structure. We describe the case of a 78-year-old man who was referred to our hospital for pulmonary vein isolation for symptomatic paroxysmal AF. He had a history of pulmonary tuberculosis for which he had undergone a right upper lobectomy. A “pancake” deformity of the left atrium (LA) was observed using 64-slice multislice computed tomography. We performed a transseptal puncture by using real-time three-dimensional transesophageal echocardiography (RT3D-TEE) in combination with fluoroscopic imaging, without any complications. Although transseptal puncture can be performed without echocardiographic guidance in most patients, in our patient, RT3D-TEE proved to be a very helpful imaging technique to access the LA.