The diagnosis of left ventricular assist device thrombosis.

The clinical course of a patient with a left ventricular assist device is described. A total of 6 weeks after device insertion, the lactate dehydrogenase (LDH) level increased to 2801 U/l despite adding low-molecular-weight heparin to acenocoumarol and aspirin. Pump thrombosis was suspected but unconfirmed by computed tomography. Increased pump power requirement did not occur. Instituting unfractionated heparin caused a drop in the LDH level. After discontinuing heparin, the LDH levels rose to 5529 U/l whereupon pump replacement was performed. LDH levels, combined with clinical deterioration and right heart catheterisation, led to the diagnosis of pump thrombosis.