A comparison of arterial versus venous‐activated clotting time in patients with congenital heart disease undergoing cardiac catheterization

Studies in adult patients undergoing percutaneous coronary angioplasty have demonstrated differences in measured activated clotting time (ACT) in venous vs. arterial blood samples. Ninety-two patients with congenital heart disease undergoing cardiac catheterization were prospectively evaluated to compare venous vs. arterial ACT values in monitoring heparin effect in this population. Simultaneous venous and arterial ACT samples were drawn at baseline, 10 min, 60 min, and every 30 min thereafter until each case was finished. ACT values were determined simultaneously with a dual-chambered Hemochron 801 instrument. At baseline and throughout the study up to 90 min, venous and arterial ACT values were not significantly different. They were also no different in the subgroup of cyanotic patients. Therefore, venous and arterial ACT values can be safely used alternatively to guide heparin dosing during cardiac catheterization in patients with congenital heart disease without the risk of undercoagulation. Cathet. Cardiovasc. Intervent. 46:194–196, 1999. © 1999 Wiley-Liss, Inc.