Infiltrative Lymphoma-Associated Bradycardia and Cardiac Conduction Abnormalities

In 2015, a 31-year-old woman presented with cough and lymphadenopathy.On positron emission tomographycomputed tomography (PET-CT), she was found to have cervical and mediastinal lymph node involvement and superior vena cava encasement.Open left neck lymph node biopsy confirmed the diagnosis of nodular sclerosing Hodgkin's lymphoma, with immunohistochemistry positive for CD30 and CD15.She underwent transthoracic echocardiography (TTE), which revealed a large pericardial effusion with evidence of tamponade.She was admitted and underwent pericardiocentesis, with drainage of 500 ml of serosanginous fluid.Repeat TTE revealed a small pericardial effusion.The patient developed sinus pauses of up to 9 s in duration, in addition to episodes of Mobitz I second-degree atrioventricular block.Cardiac magnetic resonance (CMR) imaging revealed a normal left ventricular ejection fraction (EF) of 67% and an irregularly contoured tissue prominence on the posterior aspect of left and right atria that measured 1.4 Â 0.9 cm with perivascular thickening adjacent to the aorta and superior vena cava.Tissue characterization with contrast enhancement was consistent with neoplastic invasion.The patient continued to have frequent sinus pauses consistent with direct sinoatrial node or carotid sinus involvement.A temporary transvenous pacemaker (TVP) was placed.Cycle 1 of adriamycin, bleomycin, vinblastine, dicarbazine (ABVD) chemotherapy was initiated in two 14-day infusions.The TVP was removed due to reduced sinus pauses.However, a repeat CMR showed an increase in the size of the right atrial mass (1.8 Â 1.0 cm), with a septal thickness of 1.1 cm (Figure 1).She also developed nonocclusive thrombi in both the proximal left internal jugular and right subclavian veins.Despite receiving chemotherapy, the patient continued to have prolonged sinus pauses.After a discussion between the cardiology and oncology services, the decision was made to implant a permanent pacemaker.A compassionate use exemption for a leadless pacemaker being studied at our institution as part of a clinical trial was denied.Therefore, the patient underwent placement of a single-chamber right ventricular lead pacemaker (Biotronik Eluna, Portland, Oregon) due to presence of continued sinus node dysfunction and atrioventricular block.The patient completed 6 cycles of ABVD and has remained in full remission.She has had minimal pacing requirements and has been planned for device removal and lead extraction.