What is a recognized effect of using Glycerine trinitrate in treating angina?

Glycerine trinitrate, commonly known as nitroglycerin, is a vasodilator used primarily in the treatment of angina pectoris. One of its well-established effects is to decrease venous return to the heart. This is important because by reducing the volume of blood that returns to the heart, or the preload, the heart's workload is decreased. This reduction in workload helps to alleviate symptoms of angina, as it lessens the heart's oxygen demand during episodes of chest pain.

By dilating the veins, glycerine trinitrate allows for increased capacity in the venous system, leading to decreased pressure and reduced blood volume returning to the heart. This is particularly beneficial in patients experiencing angina, as it allows for improved oxygen supply relative to demand by reducing the cardiac stress during episodes of pain.

In contrast, the other effects listed do not accurately reflect the pharmacological action of glycerine trinitrate. For example, while it does sometimes have an indirect effect on heart rate due to decreased workload, heart rate is not consistently increased with its use. The drug can decrease blood pressure as a result of vasodilation, but the direct role of decreased venous return is more significant in the context of angina treatment