Feasibility of Cardiac Resynchronization Therapy in a Patient with Complex Congenital Heart Disease and Dextrocardia, Facilitated by Cardiac Computed Tomography and Coronary Sinus Venography

We describe a case with pacemaker implantation for cardiac resynchronization therapy (CRT) in a patient with complex congenital heart disease, facilitated by cardiac computed tomography (CT) and coronary sinus (CS) venography. A 37-year-old male presented with congenitally corrected transposition of the great arteries and mesocardia, along with a history of two open heart surgeries (closure of atrial septal defects and a ventricular septal defect, and pulmonary valvectomy at age 7; mechanical tricuspid valve replacement at age 13). He showed symptoms of progressive heart failure (NYHA class III) with significant impairment of the systemic right ventricular function. He also developed permanent atrial fibrillation with a junctional rhythm at a rate of 45 beats per minute. Biventricular pacing without an atrial lead was considered to be the best option available. CRT implantation was facilitated by proper identification of CS anatomy utilizing cardiac CT and CS venography and was performed without any complications. At follow up, a postero-anterior chest X-ray showed the final position of the right-sided ventricular (left ventricular morphology) lead pointing to the apex and the left ventricular lead at the posterolateral aspect of the systemic ventricle (right ventricular morphology).