Activated clotting time (ACT), also known as activated coagulation time is a test of coagulation.[1]
The ACT test is used to monitor the effect of high-dose heparin before, during, and shortly after surgeries that require intense anticoagulant administration, such as cardiac bypass surgery, cardiac angioplasty, and dialysis.[1] It is ordered in situations where the partial thromboplastin time (PTT) test is not clinically useful or takes too long.[1]