However, given the effect of cumadin on the blood, it could well cause an increase in heart rate at first. Thinning the blood
would have the effect of allowing blood
to move more freely through the body. This means that the heart would not have to work as hard to push the liquid through the veins. If you were to stop this treatment suddenly, the heart muscle would have to adjust to the increased viscosity (thickness) of the blood by pumping harder and faster.