Understand Your Test

Activated Clotting Time

Formal Name


Activated Clotting Time


Why Get Tested?

To monitor treatment with heparin or other blood-thinning medications (anticoagulants) when undergoing heart bypass surgery, coronary angioplasty, or dialysis.

When To Get Tested?

When you are receiving high doses of heparin to prevent clotting during surgical procedures such as a heart bypass; when heparin levels are too high to allow monitoring with a PTTand/or when a rapid result is necessary to monitor treatment.