Abstract 16763: Complete Heart Block as a Complication of Diffuse Large B Cell Lymphoma

Abstract

Abbreviations: DLBCL (diffuse large B cell lymphoma), CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone). Description of case We present the case of a 78-year-old female who presented initially with a right neck mass, abdominal pain, diarrhea, and recurrent pericardial effusions requiring pericardial window procedure. Biopsy of the neck mass demonstrated a DLBCL. Involvement of a right atrial mass attached to the septum in close relation to the tricuspid valve was seen on TEE. Metastatic disease to the lungs and liver was demonstrated on CT chest and abdomen respectively. The patient posteriorly developed symptomatic bradycardia that on electrocardiogram and telemetry monitoring was shown to be due to a complete heart block with junctional and ventricular escape beats with a rate of 30-40 beats per minute. Due to the anatomical characteristics of the right atrial mass, placement of a right ventricle leadless pacemaker (micra) was decided. The patient was started on mini-CHOP chemotherapy shortly afterwards. Discussion Primary cardiac lymphomas are a rare presentation accounting for less than 1% of all cardiac malignancies. Although rare, secondary involvement of the heart is more frequent than primary involvement and represents 20-25% of the cases. From all the broad subtypes of lymphomas, DLBCL is the most commonly found to affect the cardiac system, often being represented by alterations in the conduction system and causing congestive heart failure. The exact mechanism of the conduction abnormalities in the setting of cardiac lymphoma has not yet been well elucidated but is presumed to be either caused by an infiltration of the conduction system, direct mass burden effect, or a combination of both. It has been seen in similar cases that initiation of chemotherapy can help decrease the pacing requirements or even resolve completely the conduction abnormalities. In a few cases, permanent pacing is required. Metastatic disease to the heart is a marker for poor outcome and median survival with therapy after diagnosis is between 7 to 18 months.