Western medicine learns about cardiovascular disease and blood pressure through research on enzymes and the biochemical function of blood vessels, heart and kidney cells. On the other hand, in Traditional Chinese Medicine (TCM), practitioners look for deficiencies and imbalances of energy in the spleen, liver and kidneys. When these dysfunctions of energy become chronic, they can create structural abnormalities in the organs.
In TCM philosophies, there are three basic organ energies that control the function of the heart, blood vessels and vascular system. These three energies may also have an effect on the cardiac rate and rhythm.

For example:

Spleen Energy - The spleen energy influences the lining of the blood vessels known as the endothelium. Disruptions in the spleen energy can lead to inflammation of the endothelium found in vasculitis (inflammation of the vessels).

Liver Energy - The liver energy controls the mesothelium, or smooth muscle layer of the blood vessels. Because of the liver's influence on the contraction of this muscular layer, it's one of the controls of blood pressure.

Kidney Energy - The kidney energy controls various things such as the balance of salts and fluid in the body and blood vessels and the contractile energy of the heart beat.