Left ventricular systolic dysfunction with concomitant bradyarrhythmia in a patient with POEMS syndrome: a case report.

Background: POEMS syndrome (PS) is a paraneoplastic disorder from plasma cell dyscrasia, characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes. Vascular endothelial growth factors (VEGFs)-driven fluid extracellular matrix expansion plays a key role in this condition. Associated cardiac involvement has been sparsely reported thus far.

Case Summary: A 55-year-old woman with PS presented with a pleural effusion and respiratory failure requiring mechanical ventilation. Transthoracic echocardiogram revealed left ventricular (LV) systolic dysfunction with a moderate pericardial effusion. She developed intermittent complete heart block and ventricular standstill, requiring temporary transcutaneous pacing. Further evaluation revealed no significant coronary stenosis on coronary angiogram and cardiac magnetic resonance (CMR) showed elevated T1 and extracellular volume suggestive of myocardial oedema with possible early cardiac infiltration. She had a dual-chamber permanent pacemaker implanted in view of recurrent high-grade heart block. She was initiated on a daratumumab-based chemotherapy regimen prior to discharge. She recovered well subsequently with a promising clinical response to chemotherapy.

Discussion: We describe the first case of LV systolic dysfunction with concomitant significant bradyarrhythmia in a patient with PS. CMR revealed evidence suggestive of LV myocardial oedema and/or possible early infiltration. VEGF overexpression could explain oedema-related LV dysfunction which reversed with adequate diuresis, as well as damage to the conduction system. Early cardiac amyloidosis, which can be associated with PS, is an important differential diagnosis. Pacemaker implantation, adequate diuresis, and definitive chemotherapy are key to the management of concomitant ventricular myocardial and electrical dysfunction in such rare case.