What is activated partial thromboplastin time? Coagulological test (Coagulogram): Activated partial thromboplastin time (APTT). This analysis is done on the basis of a blood plasma sample, which allows the study of its coagulation (endogenous). This test is done to determine clotting factors VIII and IX (hemophilia), monitor anticoagulant treatment using heparin, determine the anticoagulant for systemic lupus erythematosus. #thromboplastin #aptt #Thromboplastintime #activatedpartialthromboplasti