Challenging Pacemaker Implant in Sinus Node Dysfunction and Cardiac Involvement in Erdheim-Chester Disease: A Multimodality Imaging-guided Procedure.

Erdheim-Chester disease (ECD) is a rare systemic non-Langerhans cell histiocytosis of unknown etiology characterized by multiorgan xanthomatous infiltration by foamy histiocytes. Cardiovascular involvement in ECD is frequent at the level of the right atrium and superior vena cava. We present the case of a 67-year-old woman with a history of ECD and cardiac involvement, referred to our attention following syncopal episodes and paroxysmal atrial fibrillation alternating with phases of marked sinus bradycardia and asystolic pauses. Transesophageal echocardiogram and cardiac magnetic resonance imaging confirmed the increased wall thickness and the marked reduction of the internal diameter of the superior vena cava and of the right atrium. This can be a major obstacle to the implantation of a bicameral pacemaker, necessary for the sick sinus syndrome. Despite this problem, we decided to try an implant with a traditional approach from the left axillary vein; we followed the procedure with fluoroscopic and ultrasound guidance that was very useful in crossing the stenotic superior vena cava and in the positioning of the active fixation electrode in the right atrial appendage. This case confirms how a multimedial imaging approach is crucial to organize and best perform electrostimulation procedures in particular anatomical contexts such as in ECD with cardiac involvement, minimizing the risks.