Profound Sinoatrial Arrest Associated with Ibrutinib

brutinibisaBruton’styrosinekinase(BTK)inhibitorapprovedforsecond-linetreatmentformantlecelllymphoma(MCL), chronic lymphocytic leukemia (CLL), and Waldenstr ̈om macroglobulinemia. Ibrutinib use has been linked to increasedincidence of atrial 8brillation and hypertension in multiple studies. Other forms of cardiac toxicities have also been reported inisolated case reports. Bradycardia and asystole have not been associated with ibrutinib use in the past.Case Report. We presenta case of a 76-year-old female with no prior cardiac history, who initiated treatment with ibrutinib for relapsing mantle celllymphoma andwas noted to havesymptomatic bradycardia, greater than20 second long pauses on hercardiac monitor requiringplacement of a permanent pacemaker.Conclusion. *is is the 8rst case associating bradycardia and asystole with tyrosine kinaseinhibitor use. Irreversible inhibition of certain cardioprotective tyrosine kinases has been a growing topic of research in oncologytherapeutics.