Flow Pattern of Outflow Graft is Useful for Detecting Pump Thrombosis in a Patient with Left Ventricular Assist Device.

Pump thrombosis (PT) is a serious complication after continuous-flow left ventricular assist device (LVAD) implantation. To detect PT, echocardiographic ramp test using left ventricular end-diastolic diameter (LVEDD) is known to be useful. However, this method has several limitations. In this study, we propose an alternative novel ramp test using the flow velocity of outflow graft (OG). A 46-year-old man underwent continuous-flow LVAD (HeartMate II, Abbott Laboratories, Lake Forest, IL, USA) implantation for advanced heart failure due to idiopathic dilated cardiomyopathy. About 2 years after implantation, he suffered from hemolysis and symptoms of heart failure, and PT was strongly suspected. The change in LVEDD was minimal with increase in pump speed (-0.06 cm/400 rotations per minute (rpm)), suggesting PT. The systolic to diastolic velocity (S/D) ratio of OG flow, which we proposed as a new indicator of PT, also showed minimal change (-0.07/400 rpm). His clinical symptoms improved with anticoagulation therapy, and the changing slope of the S/D ratio dramatically improved to -0.92/400 rpm. Although its consistency should be verified in many other cases, this novel method can be useful for detecting PT and evaluating its clinical course.