How does nitroglycerin work to relieve chest pain?

Nitroglycerin. Nitroglycerin relieves cardiac related chest pain by dilating the coronary arteries. These are the arteries that supply blood to the heart. Improving blood flow to heart muscle will relieve the discomfort caused by a partial blockage of the blood vessel with plaque.
Ntg. Nitroglycerine opens the blood vessels of the heart, improving oxygenation thus relieving chest pain.
↓es heart workload! Nitric Oxide, long called Endothelial Relaxing Factor (http://en.wikipedia.org/wiki/Nitric_oxide & http://en.wikipedia.org/wiki/Glyceryl_trinitrate) mostly relaxes veins, thus ?ing blood return to both right & left heart, less so arteries, ?ing heart work load & may relax heart artery spasm at narrowing: ?ing blood flow to heart muscle with ?blood flow from which pressure/discomfort is perceived.