Question

The two tests that are used to monitor the effectiveness of heparin therapy are:

1) APTT and PT
2) INR and APTT
3) PT and INR
4) PTT and INR

Answer 1

To monitor heparin therapy effectiveness, the two tests used are Activated Partial Thromboplastin Time 1) (APTT) and Prothrombin Time (PT). These tests evaluate the intrinsic and common pathways of coagulation where heparin acts.

Step-by-step explanation:

The two tests that are commonly used to monitor the effectiveness of heparin therapy are the Activated Partial Thromboplastin Time (APTT) and the Prothrombin Time (PT). Therefore, the answer is 1) APTT and PT. These tests evaluate the clotting tendency of blood in different pathways of the coagulation cascade, where heparin has its effects.

The APTT measures the efficacy of the intrinsic and common pathways of coagulation, which is where heparin acts. A prolonged APTT can suggest effective heparin therapy. Heparin enhances the activity of antithrombin, which inactivates factor X and opposes the conversion of prothrombin to thrombin.

The PT test measures the speed of the extrinsic and common pathways of coagulation. The International Normalized Ratio (INR) is a standardized way of expressing PT, but it's more often used for monitoring warfarin therapy rather than heparin.