What is APT?
Activated partial thromboplastin time (aPTT) measures the intrinsic pathway
Purpose of Test
Prolonged APTT may indicate: use of heparin (or contamination of the sample) antiphospholipid antibody (especially lupus anticoagulant, which paradoxically increases propensity to thrombosis) coagulation factor deficiency (e.g. hemophilia).
Test of Result Interpretation
No preparation required