2021 Volume 85 Issue 12 Pages 2244-
A 67-year-old woman was referred to hospital for suspicion of malignant lymphoma. She developed paroxysmal atrial fibrillation-related sick sinus syndrome (SSS). The sinus arrest was documented by ECG (Figure A). Echocardiography showed a large mass (yellow arrows) in both ventricles (Figure B; RV: Supplementary Movie 1, LV: Supplementary Movie 2). Contrast-enhanced computed tomography (CT) demonstrated cervical and mediastinal lymphadenopathy and a cardiac mass. Moreover, superior vena cava (SVC) encasement was detected (Figure C). These findings suggested that cardiac involvement of malignant lymphoma was responsible for the development of SSS. Because her SVC was partially obstructed (yellow arrows, Figure C), conventional transvenous pacemaker implantation had the risk of tumor embolism and SVC syndrome. Furthermore, there was a risk of developing pacemaker-related infections by administration of anticancer drugs. Considering these factors, we decided to implant a leadless pacemaker. Implantation of a Micra leadless pacemaker via transfemoral approach was successfully performed without complications (Figure D). Cervical lymph node biopsy diagnosed the mass as a diffuse large B-cell lymphoma (Figure E,F). After chemotherapy, CT revealed marked reduction of the cardiac mass with improvement of the SSS (Figure G,H). Although her condition was temporarily stable, she died due to tumor relapse 10 months after initial admission.
(A) Electrocardiogram; (B) echocardiogram showing large mass (yellow arrows) in both ventricles; (C) contrast-enhanced CT showing partially obstructed superior vena cava (SVC, yellow arrows), RA, right atrium, RV, right ventricle, LV, left ventricle; (D) fluoroscopic image; (E,F) pathological examinations; (G,H) comparison between pre-chemotherapy and 2 weeks after chemotherapy.
A leadless pacemaker should be considered as a viable alternative to a conventional transvenous pacemaker for unusual clinical scenarios.
We have nothing to disclose.
Supplementary Movie 1. Cardiac mass in RV.
Supplementary Movie 2. Cardiac mass in LV.
Please find supplementary file(s);
http://dx.doi.org/10.1253/circj.CJ-21-0366
