Magnetic Resonance Imaging Guiding Pacemaker Implantation for Severe Sinus Node Dysfunction Due to Cardiac Involvement in Erdheim-Chester Disease

A 64-year-old woman was referred to the arrhythmia outpatient clinic after she had experienced syncope without preceding symptoms and frequent paroxysmal, near syncopal episodes over the last 8 months. The ECG revealed alternation of sinus bradycardia and frequent ectopic atrial beats, normal PR interval and right bundle branch block with consecutive repolarization abnormalities. Holter ECG showed frequent periods of asystole up to 4.3 seconds. Laboratory findings were normal. Pacemaker therapy for symptomatic sinus node dysfunction was clearly indicated. The patient’s past history revealed the diagnosis of Erdheim-Chester disease with osseous, cutaneous, mesenteric, and right atrial involvement 22 years ago. This disease belongs to …