Why get tested?
To monitor heparin and other anticoagulation when undergoing cardiopulmonary bypass, coronary angioplasty, and dialysis

When to get tested?
When you are receiving high dose heparin to prevent clotting during surgical procedures such as a cardiopulmonary bypass; when heparin levels are too high to allow monitoring with a PTT test and/or when a rapid result is necessary to monitor treatment

Sample required?
A blood sample taken from a vein in your arm