Diseases & Conditions

Heart Disease

Heart disease is a broad term used to describe a range of diseases that affect your heart, and in some cases, your blood vessels. The various diseases that fall under the umbrella of heart disease include diseases of your blood vessels, such as coronary artery disease; heart rhythm problems (arrhythmias); and heart defects you're born with (congenital heart defects).

The term "heart disease" is often used interchangeably with "cardiovascular disease" — a term that generally refers to conditions that involve narrowed or blocked blood vessels that can lead to a heart attack, chest pain (angina) or stroke. Other heart conditions, such as infections and conditions that affect your heart's muscle, valves or beating rhythm also are considered forms of heart disease.

Heart disease is the No. 1 worldwide killer of men and women, including in the United States. For example, heart disease is responsible for 40 percent of all the deaths in the United States, more than all forms of cancer combined. Many forms of heart disease can be prevented or treated with healthy lifestyle choices and diet and exercise.

Heart disease symptoms vary, depending on what type of heart disease you have.

Symptoms of heart disease in your blood vessels (cardiovascular disease)
Cardiovascular disease is caused by narrowed, blocked or stiffened blood vessels that make it so your heart, brain or other parts of your body don't receive enough blood. Cardiovascular disease symptoms can include:

• Chest pain (angina)
• Shortness of breath
• Pain, numbness, weakness or coldness in your legs or arms, if the blood vessels in those parts of your body are narrowed

You might not be diagnosed with cardiovascular disease until your condition worsens to the point that you have a heart attack, chest pain (angina), stroke, heart failure or sudden cardiac death. It's important to watch for cardiovascular symptoms and discuss any concerns with your doctor. Cardiovascular disease can sometimes be found early with regular visits to your doctor.

Heart disease symptoms caused by abnormal heartbeats (heart arrhythmias)
A heart arrhythmia is an abnormal heartbeat. Your heart may beat too quickly, too slowly, or irregularly if you have an arrhythmia. Heart arrhythmia symptoms can include:

• A fluttering in your chest
• A racing heartbeat (tachycardia)
• A slow heartbeat (bradycardia)
• Chest pain
• Shortness of breath
• Lightheadedness
• Dizziness
• Fainting (syncope) or near fainting

Heart disease symptoms caused by heart defects
Serious congenital heart defects — a defect you're born with — usually become evident during the first few hours, days, weeks and months of life. Heart defect symptoms could include:

• Pale gray or blue skin color (cyanosis)
• Swelling in the legs, abdomen or areas around the eyes
• Shortness of breath during feedings, leading to poor weight gain

Less-serious congenital heart defects are often not diagnosed until later in childhood, or even adulthood. Signs and symptoms of congenital heart defects that usually aren't immediately life-threatening include:

• Easily becoming short of breath during exercise or activity
• Easily tiring during exercise or activity
• Built-up fluid in the heart or lungs
• Swelling in the hands, ankles or feet

Heart disease symptoms caused by thick heart muscle (cardiomyopathy)
Cardiomyopathy is the thickening and stiffening of heart muscle. In early stages of cardiomyopathy, you may have no symptoms. As the condition worsens, cardiomyopathy symptoms include:

• Breathlessness with exertion or even at rest
• Swelling of the legs, ankles and feet
• Bloating (distention) of the abdomen with fluid
• Fatigue
• Irregular heartbeats that feel rapid, pounding or fluttering
• Dizziness, lightheadedness and fainting

Heart disease symptoms caused by heart infections
There are three types of heart infections: pericarditis, which affects the tissue surrounding the heart (pericardium); myocarditis, which affects the muscular middle layer of the walls of the heart (myocardium); and endocarditis, which affects the inner membrane that separates the chambers and valves of your heart (endocardium). Varying slightly with each type of infection, heart infection symptoms can include:

• Fever
• Shortness of breath
• Weakness or fatigue
• Swelling in your legs or abdomen
• Changes in your heart rhythm
• Dry or persistent cough
• Skin rashes or unusual spots

Heart disease symptoms caused by valvular heart disease
The heart has four valves — the aortic, mitral, pulmonary and tricuspid valves — that open and close to direct blood flow through your heart. Valves may be damaged by a variety of conditions leading to narrowing (stenosis), leaking (regurgitation or insufficiency) or improper closing (prolapse). Depending on which valve isn't working properly, valvular heart disease symptoms generally include:

• Fatigue
• Shortness of breath
• Irregular heartbeat or heart murmur
• Swollen feet or ankles
• Chest pain
• Fainting (syncope)

When to see a doctor
Seek emergency medical care if you have these heart disease symptoms:

• Chest pain
• Shortness of breath
• Fainting

Heart disease is easier to treat when it's detected early, so talk to your doctor about any concerns you have about your heart health. If you don't have heart disease, but are concerned about developing heart disease, talk to your doctor about steps you can take to reduce your heart disease risk. This is especially true if you have a family history of heart disease.

If you think you may have heart disease based on new signs or symptoms you've been having, make an appointment to see your doctor.

To understand heart disease, it helps to know how the heart works. Your heart is a pump. It's a muscular organ about the size of your fist and located slightly left of center in your chest. Your heart is divided into the right and the left side. The division protects oxygen-rich blood from mixing with oxygen-poor blood. Oxygen-poor blood, "blue blood," returns to the heart after circulating through your body.

The right side of the heart, composed of the right atrium and ventricle, collects and pumps blood to the lungs through the pulmonary arteries. The lungs refresh the blood with a new supply of oxygen, making it turn red. Oxygen-rich blood then enters the left side of the heart, composed of the left atrium and ventricle, and is pumped through the aorta to the body to supply tissues throughout the body with oxygen and nutrients.

Four valves within your heart keep your blood moving the right way. The tricuspid, mitral, pulmonary and aortic valves work like gates on a fence. They open only one way and only when pushed on. Each valve opens and closes once per heartbeat — or about once every second while you're at rest.

A beating heart contracts and relaxes. Contraction is called systole, and relaxation is called diastole. During systole, your ventricles contract, forcing blood into the vessels going to your lungs and body — much like ketchup being forced out of a squeeze bottle. The right ventricle contracts a little bit before the left ventricle does. Your ventricles then relax during diastole and are filled with blood coming from the upper chambers, the left and right atria. The cycle then starts over again.

Your heart also has electrical wiring, which keeps it beating. Electrical impulses begin high in the right atrium and travel through specialized pathways to the ventricles, delivering the signal to pump. The conduction system keeps your heart beating in a coordinated and normal rhythm, which in turn keeps blood circulating. The continuous exchange of oxygen-rich blood with oxygen-poor blood is what keeps you alive.

The causes of heart disease vary by type of heart disease. 

Causes of cardiovascular disease
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 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 arrhythmias
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
• Diabetes
• Smoking
• Excessive use of alcohol or caffeine
• Drug abuse
• Stress
• 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 illicit 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. Researchers aren't sure exactly what causes defects to begin, but they think some medical conditions, medications and genetics may play a role.

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 infections
Heart infections, such as pericarditis, endocarditis and myocarditis, are caused when an irritant, such as a bacteria, 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 illicit substances, such as cocaine. The needles used to administer medications or illicit 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 diseases
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.

Heart disease can be improved — or even prevented — by making certain lifestyle changes. The following changes can help anyone who wants to improve their heart health:

• Stop smoking. Smoking is a major risk factor for heart disease, especially atherosclerosis. Nicotine constricts blood vessels and forces your heart to work harder, and carbon monoxide reduces oxygen in your blood and damages the lining of your blood vessels. If you smoke, quitting is the best way to reduce your risk of heart disease and its complications.
• Control your blood pressure. Ask your doctor for a blood pressure measurement at least every two years. He or she may recommend more frequent measurements if your blood pressure is higher than normal or you have a history of heart disease. Optimal blood pressure is below 120 systolic and 80 diastolic, as measured in millimeters of mercury (mm Hg).
• Check your cholesterol. Ask your doctor for a baseline cholesterol test when you're in your 20s and then at least every five years. If your test results aren't within desirable ranges, your doctor may recommend more frequent measurements. Most people should aim for an LDL level below 130 milligrams per deciliter (mg/dL), or 3.4 millimoles per liter (mmol/L). If you have other risk factors for heart disease, your target LDL may be below 100 mg/dL (2.6 mmol/L). If you're at very high risk of heart disease — if you've already had a heart attack or have diabetes, for example — your target LDL level is below 70 mg/dL (1.8 mmol/L).
• Keep diabetes under control. If you have diabetes, tight blood sugar control can help reduce the risk of heart disease.
• Get moving. If you have heart disease, exercise helps you achieve and maintain a healthy weight and control diabetes, elevated cholesterol and high blood pressure — all risk factors for heart disease. If you have a heart arrhythmia or heart defect, there may be some restrictions on the activities you can do, so be sure to talk to your doctor first. With your doctor's OK, aim for 30 to 60 minutes of physical activity most days of the week. Even if you can't make time for one 30- to 60-minute exercise session, you can still benefit from breaking up your activity into several 10-minute sessions.
• Eat healthy foods. A heart-healthy diet based on fruits, vegetables and whole grains — and low in saturated fat, cholesterol and sodium — can help you control your weight, blood pressure and cholesterol. Eating one or two servings of fish a week also is beneficial.
• Maintain a healthy weight. Being overweight increases your risk of heart disease. Weight loss is especially important for people who have large waist measurements - more than 40 inches (101.6 centimeters, or cm) for men and more than 35 inches (88.9 cm) for women — because people with this body shape are more likely to develop diabetes and heart disease.
• Manage stress. Reduce stress as much as possible. Practice healthy techniques for managing stress, such as muscle relaxation and deep breathing.
• Practice good hygiene habits. Staying away from other people when they are sick and regularly washing your hands can not only prevent heart infections but also can help prevent viral or bacterial infections that can put stress on your heart if you already have heart disease. Also, brushing and flossing your teeth regularly can prevent germs in your mouth from making their way to plaques in your heart, which could worsen cardiovascular disease.
• Get a flu shot. If you have cardiovascular disease, you're at a greater risk of having a heart attack should you catch the flu. Getting a flu shot decreases this risk.

In addition to healthy lifestyle changes, remember the importance of regular medical checkups. Early detection and treatment can set the stage for a lifetime of better heart health.