Related Experiment Video
Updated: Dec 2, 2025

In Vitro Thrombosis Test for Ventricular Assist Devices
Published on: March 21, 2025
Venous or arterial samples for activated clotting time measurements: a systematic review
Sashini Iddawela1, Priti Swamy2, Sajid Member3
1Department of Respiratory Medicine, University Hospitals Birmingham, Birmingham, UK.
Objective:
The systematic review aims to investigate the effect of sampling source on activated clotting time (ACT) measurement within cardiovascular surgery and cardiac catheterisation. It also examines the evidence surrounding novel clot assessment techniques and associated sampling variation.
Methods:
A comprehensive electronic search was conducted using PubMed, MEDLINE, Scopus, Cochrane database, and Google Scholar until 20th June 2020. All studies reporting sampling source variability of ACT in cardiac surgery, vascular surgery and cardiac catheterisation were included.
Results:
Fourteen studies were included in the systematic review. Inconsistent reports of variability were seen in cardiac surgery and cardiac catheterisation. There were no studies directly examining ACT variability in vascular surgery. Novel clot assessment techniques have been validated in cardiac surgery, but measurements vary depending on sampling source.
Conclusion:
Sampling source should be kept consistent to facilitate effective haemostatic strategies. More research is needed regarding variability in vascular surgery and novel clot assessment techniques.
Related Concept Videos
Venous Thrombosis III: Interprofessional Care
Venous Thrombosis II: Clinical Manifestations and Diagnostic Studies
Venous Thrombosis I: Introduction
Venous Thrombosis IV: Nursing Management
Extrinsic and Intrinsic Pathways of Hemostasis
The Extrinsic Pathway
The extrinsic pathway of coagulation is typically initiated by tissue damage that exposes blood to tissue factor (TF), a protein released by the damaged tissue cells outside the blood vessels—this interaction with TF triggers biochemical reactions involving specific clotting factors. The key player here is Factor VII, which...
Anticoagulant Drugs: Vitamin K Antagonists and Direct Oral Anticoagulants
Warfarin, a prominent vitamin K antagonist family member, exerts its effect by inhibiting the enzyme VKORC1 (vitamin K epoxide reductase complex 1). By hindering this enzyme, warfarin...

