The law of Laplace is a law in physics that is also applied in medicine in blood flow physiology. According to LearntheHeart, this law illustrates the components that determine left ventricular wall stress, which is a crucial determinant of myocardial oxygen demand.
Further, this law is significant in that it helps health professionals understand the conditions that change oxygen demand that lead to angina and discover therapies that could relieve angina. The law of Laplace implies that transluminal pressure is directly proportional to tension found in vessel walls but is inversely proportional to vessel radius. This means that the pressure exerts tension by pushing against the wall until it stretches. Thus, as the vessel's size decreases, tension in the wall also decreases.