RESUMO
INTRODUCTION: Ibrutinib, an oral inhibitor of Bruton's tyrosine kinase, has altered the treatment perspective of chronic lymphocytic leukemia and showed modest activity against several types of non-Hodgkin's lymphomas. According to phase studies and real-world data, reported serious adverse effects included atrial fibrillation, diarrhea, and bleeding diathesis. However, heart failure was not reported to be a probable adverse effect linked with ibrutinib. CASE REPORT: In this paper, we present a 66-year-old female chronic lymphocytic leukemia patient who developed significant and symptomatic left ventricular dysfunction at the 13th month of ibrutinib treatment. MANAGEMENT AND OUTCOME: Following cessation of ibrutinib, ejection fraction and clinical findings of the left ventricular dysfunction alleviated. DISCUSSION: Although the use of ibrutinib is generally well tolerated, cardiac functions should be monitored occasionally in all patients.