To learn about the causes of heart disease, let’s take a look at the way your heart works.
How the heart works
Your heart is like a pump. It’s a muscle about the size of your clenched fist, situated slightly left of center in your chest. Your heart is divided into two sides, separated by an inner wall called the septum. The division protects oxygen-rich blood from mixing with oxygen-poor blood. Oxygen-poor blood returns to the heart after circulating through your body.
- The right side of the heart, including the right atrium and ventricle, collects and pumps blood to the lungs to pick up oxygen through the pulmonary arteries.
- The lungs are responsible for refreshing the blood with a new supply of oxygen. The lungs also breathe out carbon dioxide, a waste product.
- Oxygen-rich blood then enters the left side of the heart, comprising the left atrium and ventricle.
- The left side of the heart receives the oxygen-rich blood from the lungs and pumps it to the body.
Four valves within your heart keep your blood moving from the atria to the ventricles and from the ventricles into the two large arteries connected to the heart by opening only one way and only when they need to. The four valves include:
A beating heart contracts and relaxes in a continuous cycle.
- During contraction (systole), your ventricles contract, forcing blood into the vessels to your lungs and body.
- During relaxation (diastole), the ventricles are filled with blood coming from the upper chambers (left and right atria).
Various heart disease causes
The causes of heart disease vary depend on what type of heart disease you have.
Causes of cardiovascular disease
Though cardiovascular disease can make mention of different heart or blood vessel problems, it is often used to refer to the damage to your heart or blood vessels by atherosclerosis (also known as arteriosclerotic vascular disease or ASVD), a buildup of fatty plaques in your arteries. Plaque buildup thickens and stiffens artery walls, which can limit the flow of oxygen-rich blood to your organs and other parts of your body.
Atherosclerosis is also the leading cause of cardiovascular disease. The cause of atherosclerosis isn’t known but you can control some risk factors such as an unhealthy diet, lack of physical activities, being overweight and smoking.
Causes of heart arrhythmia
Common causes of abnormal heart rhythms (arrhythmias) or conditions include:
- Heart defects you’re born with (congenital heart defects)
- Coronary artery disease
- Changes in your heart muscle
- Valvular heart disease
- Healing process after heart surgery.
- High blood pressure
- Excessive use of alcohol or caffeine
- Drug abuse
- Some over-the-counter medications, prescription medications, dietary supplements and herbal treatments
- Electrical shock
In a body with a normal, healthy heart, it’s not probable for a fatal arrhythmia to progress without some external trigger, such as an electrical shock or drug abuse. That’s primarily since a healthy person’s heart is free from any abnormal conditions that lead to an arrhythmia, such as an area of scarred tissue.
Nonetheless, in a heart that’s diseased or deformed, the heart’s electrical impulses may not properly start or transmit through the heart, making arrhythmias more likely to progress.
Causes of congenital heart defects
Heart defects usually develop while a baby is in the womb. Heart defects can develop as the heart develops, about a month after conception, changing the flow of blood in the heart. Some medical conditions, medications and genes may be the main causes of heart defects.
Adults can also suffer from Heart defects. As you get older, your heart’s structure can change, causing a heart defect.
Causes of cardiomyopathy
Often, the cause of the cardiomyopathy is unknown. In some cases, however, doctors are able to identify some contributing factors. Possible causes of cardiomyopathy depend on the type as the following:
- Dilated cardiomyopathy.The cause of this most common type of cardiomyopathy often is unidentified. It may occur as a result of certain conditions such as ischemic heart disease, infections, chemotherapy, toxins and certain drugs. The people who have dilated cardiomyopathy may also inherit it from their parents.
- Hypertrophic cardiomyopathy.This type, in which the heart muscle becomes abnormally thick making it harder for the heart to pump blood, usually is inherited. It can also develop over time because of high blood pressure or aging.
- Restrictive cardiomyopathy.This is the least common type of cardiomyopathy, which causes the heart muscle to become rigid and less elastic, thus the heart can’t properly expand and fill with blood between heartbeats. The condition can occur for no known reason. Or it may be caused by diseases, such as connective tissue disorders or excessive iron buildup in your body (hemochromatosis), a disorder that causes the buildup of abnormal proteins (amyloidosis) or by some cancer treatments, such as chemotherapy and radiation.
Causes of heart infection
Heart infections, such as pericarditis, endocarditis and myocarditis, are caused when an irritant, such as a bacterium, virus or chemical, reaches your heart muscle. The most common causes of heart infections include:
Causes of valvular heart disease
There are many causes of diseases of your heart valves. You may be born with born with an abnormal valve or valves, or the condition may be caused by other such as:
- rheumatic fever
- cardiomyopathy – a disease of the heart muscle
- damage to the heart muscle from a heart attack
- a previous infection with endocarditis.