Angina is a state of imbalance between the heart’s demands of oxygen which is essential for the production of energy by the heart’s muscle, and the supply of this vital nutrient. The heart’s blood supply comes from blood vessels called coronary arteries, and they originate from the aorta, which is the main blood supply for the whole body, except for the lungs.
The most common cause for such insufficiency is what we call coronary artery disease or “CAD.” It is mostly caused by the narrowing of the coronaries by the deposition of fat into their walls which is better known as atherosclerosis. Usually, this is a normal senile process that occurs over the years following the mid-twenties in human lives. However, it is sped up in some people who may start experiencing anginal pain in their forties or fifties and more recently owing to the trends of fast food and sedentary lifestyle.
It is hard to point out at a unique cause for angina because of two reasons; the first one is that there is more than one type of angina, and each type has its own causes. The second reason is that for the coronaries to be narrowed by fat, they need a multitude of factors.
To make things a little bit easier, let’s take the “risk factors” for atherosclerosis one by one and see how can they cause such condition or rather, become a predisposing factor:
Tobacco smoking causes hypertension, injures the walls of your arteries, and makes them more liable for atherosclerosis by depositing lipids (fats). It also promotes insulin resistance which increases the risk of type 2 diabetes, makes your blood “thicker” and makes your platelets more liable to “stick” together, thereby increasing the risk of having a fatal heart attack by clogging your arteries, cutting this way all blood supply to a part of your heart. That’s why it is widely accepted that smoking is the leading cause of preventable death in the world.
Diabetes a clinical condition where your body either can’t produce insulin or has developed resistance to the action of this hormone. This leads to the inability of the body to use glucose sugar which makes it resort to using other sources for energy. The most important alternative source for energy is fats, so it “mobilizes” fats from their stores, increasing their levels in the blood and accelerating atherosclerosis.
Obesity increases the amount of circulating fats in your body, especially LDL cholesterol, which is the harmful type of cholesterol. Abdominal obesity also increases insulin resistance predisposing to diabetes type 2.
4. Sedentary lifestyle / Physical inactivity
Regular exercise boosts the heart’s health and helps establish new vascular connections in the heart. It also increases the level of HDL cholesterol (the good cholesterol) at the expense of LDL cholesterol, reduces weight, and therefore delays and slows atherosclerosis. It is advisable to exercise regularly for at least 20-30 minutes a day to achieve good cardiac health.
Chronically high blood pressure causes excessive stress on blood vessels which injures the vessel walls, predisposing to atherosclerosis.
Read also; What Are The Complications of Hypertension?
6. Chronic or repetitive stress
Emotional stress causes a surge of blood pressure and excessive release of stress hormones that narrows arteries, and decreases blood supply to the heart, aggravating angina.
7. Family history
A family history of angina or similar conditions is a strong risk factor for angina. It may be related to multiple conditions, such as familial hypercholesterolemia, where individuals of a certain family have a tendency to have high levels of blood cholesterol due to metabolic defects.
8. Excessive alcohol consumption
Alcohol, when used in excess, might predispose to hypertension and alters the balance of HDL and LDL cholesterol, thereby increasing anginal risk.
9. Advanced age
As mentioned before, the pathology causing angina is gradual, and although the pain is acute or sudden, the events leading to it takes years. Therefore, as age advances, the risk of developing angina increases.
10. Male sex
Males are more liable to atherosclerosis and experience it at a younger age than women for two reasons. The first being the presence of male sex hormone (testosterone), which increases the level of LDL cholesterol, and the second is the absence of female sex hormones which have a protective effect against atherosclerosis.
All or some of these risk factors act together to form the pathology that causes angina. However, the cause for the onset of symptoms differ according to the type of angina as follows:
Stable anginal pain is caused by exertion, exercise, cold weather, heavy meals, or emotional stress and is relieved by rest and nitroglycerides. It is the result of a gradual process of coronary narrowing. On the other hand, Unstable angina is caused by a sudden “rupture” of a plaque of fat which causes sudden narrowing of the coronary arteries. It is an emergency and needs immediate hospital referral. Prinzmetal’s variant angina is not caused by narrowing of the coronaries by atherosclerosis, but by contraction of the muscles found in the walls of the coronary arteries which is known as “coronary spasm.” It may be caused by stress, hypertension, smoking, cold exposure or cocaine use. Some people may have a combination of atherosclerotic and Prinzmetal angina. Other rare causes of angina include inflammation of the coronary arteries, diseases of the heart valves, direct heart injury or compression of the coronary arteries from outside the heart by tumors, lymph nodes..etc.