Subcutaneous Cardiac Monitoring of Patients With BTK Inhibitors

Inclusion Criteria: * Adult patients, * Definite diagnosis of hematologic malignancy requiring a BTK inhibition with ibrutinib, acalabrutinib or zanubrutinib, * Expected BTK inhibitor duration estimated to be at least 12 months, * Sinus rhythm at enrolment, * Willing to sign patient consent form and to comply with scheduled visits, as outlined in the protocol Exclusion Criteria: * Age \< 18 years old, * Adults with protective measures (curatorship or tutorship) and vulnerable patients, * Pregnant or nursing women, * Permanent atrial fibrillation or long-standing persistent atrial fibrillation as defined by the European Society of Cardiology guidelines, * Atrial fibrillation on the electrocardiogram at the inclusion visit, * Previous left atrial ablation or previous maze or maze-like surgery, * Indication for or patients with a pacemaker or implantable cardioverter-defibrillator at baseline, * Untreated hyperthyroidism, * Uncorrected kaliaemia disorders at the inclusion visit, * Hemoglobin \< 8 g/L at the inclusion visit, * Thrombopenia \< 50,000/mm3 at the inclusion visit, * Active bleeding, * Myocardial infarction \< 1 month, * Surgery \< 1 month, * Mechanical heart valve, * Valvular heart disease requiring surgery, * Inability to follow the required procedures of the clinical investigation plan, * No signature of patient consent form.