Inclusion Criteria:  Patients with implanted cardioverter-defibrillator and third-generation centrifugal CF-LVAD with hydrodynamic bearing (HVAD, Medtronic, Minnesota, United States), at least three months after surgery.  Exclusion Criteria:  Hemodynamic instability. Non-therapeutic anticoagulation. Device or intracardiac thrombus. Inflammation. Active bleeding.