The heart is like any other muscle, requiring blood to supply oxygen and nutrients for it to function.
The heart's needs are provided by the coronary arteries, which begin at the base of the aorta and spread across the surface of the heart, branching out to all areas of the heart muscle.
The coronary arteries are at risk for narrowing as cholesteroldeposits, called plaques, build up inside the artery. If the arteries narrow enough, blood supply to the heart muscle may be compromised (slowed down), and this slowing of blood flow to the heart causes pain, or angina.
A heart attack or myocardial infarction occurs when a plaque ruptures, allowing a blood clot to form. This completely obstructs the artery, stopping blood flow to part of the heart muscle, and that portion of muscle dies.
Risk factors for heart disease include:
The typical symptoms of coronary artery disease are associated chest pain with shortness of breath. Classically, the pain of angina is described as a pressure or heaviness behind the breast bone with radiation to the jaw and down the arm accompanied by shortness of breath and sweating.
Unfortunately, angina has a variety of presentations, and there may not even be specific chest pain. There may be shoulder or back ache, nausea, indigestion or upper abdominal pain.
Women, the elderly, and people with diabetes may have different perceptions of pain or have no discomfort at all. Instead, they may complain of malaise or fatigue.
Healthcare providers and patients may have difficulty understanding each other when symptoms of angina are described. Patients may experience pressure or tightness but may deny any complaints of pain.
People with coronary artery disease usually have gradual progression of their symptoms over time. As an artery narrows over time, the symptoms that it causes may increase in frequency and/or severity.
Healthcare providers may inquire about changes in exercise tolerance (How far can you walk before getting symptoms? Is it to the mailbox? Up a flight of stairs?) and whether there has been an acute change in the symptoms.
Once again, patients may be asymptomatic until a heart attack occurs. Of course, some patients also may be in denial as to their symptoms and procrastinate in seeking care.
While cardiovascular disease can refer to many different types of heart or blood vessel problems, the term is often used to mean damage caused to your heart or blood vessels by atherosclerosis (ath-ur-o-skluh-RO-sis), a buildup of fatty plaques in your arteries. This is a disease that affects your arteries. Arteries are blood vessels that carry oxygen and nutrients from your heart to the rest of your body. Healthy arteries are flexible and strong.
Over time, however, too much pressure in your arteries can make the walls thick and stiff — sometimes restricting blood flow to your organs and tissues. This process is called arteriosclerosis, or hardening of the arteries. Atherosclerosis is the most common form of this disorder. Atherosclerosis is also the most common cause of cardiovascular disease, and it's often caused by an unhealthy diet, lack of exercise, being overweight and smoking. All of these are major risk factors for developing atherosclerosis and, in turn, cardiovascular disease.
Causes of heart arrhythmia
Common causes of abnormal heart rhythms (arrhythmias), or conditions that can lead to arrhythmias include:
- Heart defects you're born with (congenital heart defects).
- Coronary artery disease.
- High blood pressure.
- Excessive use of alcohol or caffeine.
- Drug abuse.
- Some over-the-counter medications, prescription medications, dietary supplements and herbal remedies.
- Valvular heart disease.
In a healthy person with a normal, healthy heart, it's unlikely for a fatal arrhythmia to develop without some outside trigger, such as an electrical shock or the use of illegal drugs. That's primarily because a healthy person's heart is free from any abnormal conditions that cause an arrhythmia, such as an area of scarred tissue.
However, in a heart that's diseased or deformed, the heart's electrical impulses may not properly start or travel through the heart, making arrhythmias more likely to develop.
Causes of heart defects
Heart defects usually develop while a baby is still in the womb. About a month after conception, the heart begins to develop. It's at this point that heart defects can begin to form. Some medical conditions, medications and genes may play a role in causing heart defects.
Heart defects can also develop in adults. As you age, your heart's structure can change, causing a heart defect.
Causes of cardiomyopathy
The exact cause of cardiomyopathy, a thickening or enlarging of the heart muscle, is unknown.
There are three types of cardiomyopathy:
- Dilated cardiomyopathy. This is the most common type of cardiomyopathy. In this disorder, your heart's main pumping chamber — the left ventricle — becomes enlarged (dilated), its pumping ability becomes less forceful, and blood doesn't flow as easily through the heart.
- Hypertrophic cardiomyopathy. This type involves abnormal growth or thickening of your heart muscle, particularly affecting the muscle of your heart's main pumping chamber. As thickening occurs, the heart tends to stiffen and the size of the pumping chamber may shrink, interfering with your heart's ability to deliver blood to your body.
- Restrictive cardiomyopathy. The heart muscle in people with restrictive cardiomyopathy becomes stiff and less elastic, meaning the heart can't properly expand and fill with blood between heartbeats. It's the least common type of cardiomyopathy and can occur for no known reason.
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:
Bacteria. Endocarditis can be caused by a number of bacteria entering your bloodstream. The bacteria can enter your bloodstream through everyday activities, such as eating or brushing your teeth, especially if you have poor oral health. Myocarditis can also be caused by a tick-borne bacterium that is responsible for Lyme disease.
Viruses. Heart infections can be caused by viruses, including some that cause influenza (coxsackievirus B and adenovirus), a rash called fifth disease (human parvovirus B19), gastrointestinal infections (echovirus), mononucleosis (Epstein-Barr virus) and measles (rubella). Viruses associated with sexually transmitted infections also can travel to the heart muscle and cause an infection.
Parasites. Among the parasites that can cause heart infections are Trypanosoma cruzi, toxoplasma, and some that are transmitted by insects and can cause a condition called Chagas' disease.
Medications that may cause an allergic or toxic reaction. These include antibiotics, such as penicillin and sulfonamide drugs, as well as some illegal substances, such as cocaine. The needles used to administer medications or illegal drugs also can transmit viruses or bacteria that can cause heart infections.
Other diseases. These include lupus; connective tissue disorders; inflammation of blood vessels (vasculitis); and rare inflammatory conditions, such as Wegener's granulomatosis.
Causes of valvular heart disease
There are many causes of diseases of your heart valves. Four valves within your heart keep blood flowing in the right direction. You may be born with valvular disease, or the valves may be damaged by such conditions as rheumatic fever, infections (infectious endocarditis), connective tissue disorders, and certain medications or radiation treatments for cancer.
What is the treatment for heart disease?
Coronary artery disease is usually treated in a multi-step approach depending upon a patient's symptoms. The patient and healthcare provider need to work together to return the patient to a normal lifestyle.
Prevention of heart disease
The key to the treatment is prevention. A healthy lifestyle is the key, including exercise, proper nutrition, and smoking cessation.
An aspirin a day is recommended to decrease the risk for heart disease and should be started with the recommendation of a healthcare provider.
A little alcohol (one drink per day for women or two drinks per day for men) decreases the risk of heart disease compared to nondrinkers. However, it is not recommended that nondrinkers begin drinking.
Modifying risk factors for heart disease
While patients cannot choose their family and alter their genetic predisposition to coronary artery disease, the rest of the risk factors are under control of the patient. Keeping blood pressure, cholesterol and other lipid levels, and diabetes under control needs to become a life-long goal. Smoking cessation is highly encouraged.