Complete AV Block From Septal Cardiac Metastases of Anal Squamous Carcinoma Managed With Leadless Pacing

Cardiac metastases from anal squamous cell carcinoma (ASCC) are exceedingly rare; complete atrioventricular (AV) block from septal involvement has not previously been reported In Vivo.

A 79-year-old woman with p16-negative ASCC developed complete AV block with asystolic pauses during chemoradiotherapy. Restaging computed tomography showed a 49-mm interventricular septal mass and 2 left ventricular lesions, consistent with cardiac metastases. A Micra AV leadless pacemaker was implanted because of pacemaker dependence, frailty, infection risk, and challenging vascular access. Cemiplimab, an anti-PD-1 immunotherapy, was initiated for progressive metastatic disease.

Septal metastatic infiltration was the most likely cause of the AV block. New conduction disease in patients with cancer warrants multimodality imaging to assess cardiac involvement.

Leadless pacing can be a practical option for complete AV block in frail oncology patients. Cardiac metastases should be considered in new arrhythmias or conduction disturbances, particularly with septal lesions.