Severe venous and lymphatic obstruction after single-chamber pacemaker implantation in a patient with chest radiation therapy.

A 73-year-old woman with a history of paroxysmal atrial fibrillation, sinus node dysfunction, bilateral breast cancer, and extensive chest radiation developed progressive edema, dyspnea, and recurrent pleural effusions soon after single-chamber pacemaker implantation. Thoracentesis yielded a diagnosis of chylothorax, and progressive refractory anasarca developed. A computed tomography angiogram suggested obstruction of the superior vena cava and left subclavian vein despite outpatient therapeutic anticoagulation. Autopsy confirmed venous thrombosis, along with mediastinal fibrosis. The presumed etiology of the chylothorax and anasarca was obstruction of the atretic central venous structures following pacemaker implantation, critically impairing the already tenuous venous and lymphatic drainage. (PACE 2010; 520-524).