An 84-year-old male with an unknown fever and vomiting presented to our
institution. His electrocardiogram demonstrated sinus pauses up to 10
seconds. We thought the sinus arrest was caused by hyperkalemia
(potassium of 6.9 mEq/L) followed by worsening renal function (blood
urea nitrogen 84.6 mg/dL and creatinine 4.77 mg/dL). We immediately
placed a temporary pacemaker and performed continuous hemodiafiltration,
however, regardless of multidisciplinary treatment, he died on the
thirty-eighth day of admission. His autopsy revealed cardiac involvement
of diffuse large B-cell lymphoma (DLBCL). The diffuse infiltrated large
lymphoid cells were observed to have right atrial dominance (Figure A).
In this clinical course, the electrocardiogram demonstrated atrial
tachycardia with 3:1 conduction and atrial fibrillation (Figure B). Both
tachycardias were followed by sinus arrest. The patient presented with
various types of arrhythmias such as sick sinus syndrome, atrial
tachycardia, and atrial fibrillation. Theoretically, the infiltrated
DLBCL invaded the sinus node and right atrium, then induced these
various arrhythmias in this case. Alternatively, cardiac involvement of
malignant lymphoma is usually non-symptomatic1. It is
important not to dismiss a rare symptomatic case of cardiac involvement
of malignant lymphoma since there were various types of arrhythmias that
might have been treated with chemotherapy2.