BACKGROUND Cardiac
lymphomas can lead to
heart block through
tumor disruption of the cardiac conduction system. It is reported that with
cardiac tumor treatment, conduction abnormalities can resolve. We present a case of cardiac
lymphoma resulting in complete
heart block requiring a pacemaker, followed by reduction of the pacing burden after
chemotherapy. CASE REPORT A 72-year-old woman with a medical history of
hypertension,
hypothyroidism, and
persistent atrial fibrillation presented with
dyspnea on exertion and
fatigue for 2 weeks. Electrocardiography revealed complete
heart block with junctional
bradycardia of 48 beats per min. Transthoracic echocardiography demonstrated preserved left ventricular systolic function along with a large mass (3.6×3.7 cm). An endomyocardial biopsy was consistent with
diffuse large B cell lymphoma, and the cardiac involvement was thought to be secondary based on positron emission tomography scan findings. Her
clinical course was complicated by an episode of
syncope deemed to be due to transient
asystole, and an urgent single-chamber permanent pacemaker was implanted.
Chemotherapy was initiated with R-CHOP, and, following the second cycle of
chemotherapy, a positron emission tomography scan revealed no increased radiotracer uptake and thus resolution of all
tumors. An echocardiogram 6 weeks after
chemotherapy showed complete resolution of the cardiac mass. Subsequent serial pacemaker checks demonstrated improvement of atrioventricular nodal function as manifested by reduced pacing burden. CONCLUSIONS
Lymphoma with cardiac involvement can lead to conduction abnormalities, including CHB, and
heart block in the setting of these
tumors may be reversible with appropriate
therapy; however, implantation of a pacemaker remains inevitable is some cases.