A heart attack happens when there is a sudden complete blockage of an artery that supplies blood to an area of your heart.

A heart is a muscle, and it needs a good blood supply to keep it healthy.

As we get older, the smooth inner walls of the arteries that supply the blood to the heart can become damaged and narrow due to the build up of fatty materials, called plaque.

When an area of plaque breaks, blood cells and other parts of the blood stick to the damaged area and form blood clots. A heart attack occurs when a blood clot completely blocks the flow of blood and seriously reduces blood flow to the heart muscle. This also results in patients experiencing chest pain.

As a result, some of the heart muscle starts to die.

The longer the blockage is left untreated, the more the heart muscle is damaged. If the blood flow is not restored quickly, the damage to the heart muscle is permanent.

A heart attack is sometimes called a myocardial infarction (MI), acute myocardial infarction, coronary occlusion or coronary thrombosis.

A heart attack happens when there is a sudden complete blockage of an artery that supplies blood to an area of your heart.
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Causes
The underlying cause of a heart attack is coronary heart disease.

Some people may not know they have coronary heart disease until they have a heart attack. For others, a heart attack can happen after weeks, months or years of having coronary heart disease.

Symptoms
Heart attack warning signs can vary from person to person, and they may not always be sudden or severe. Read about heart attack warning signs

Diagnosis
If you are rushed to hospital with a suspected heart attack, your health care team will do some tests to find out if you are having a heart attack. They may include:

electrocardiogram (ECG)
blood tests
chest X-ray
coronary angiogram.
These tests will help them to decide the best treatment for you. Find out more about medical tests

Treatment
Emergency treatment
If you think you’re having a heart attack, call Triple Zero (000). Don’t hang up. Ask the operator for an ambulance. Too many people lose their lives because they wait too long to get treatment for heart attack.

You may be given medicines to help dissolve clots.

There is a high risk of dangerous changes to your heartbeat after the start of a heart attack. The most serious changes stop your heart beating and cause a cardiac arrest. Ambulance or hospital staff may use a defibrillator to give your heart a controlled electric shock that may make it start beating again.

In hospital
In hospital, you will receive treatments that help to reduce damage to your heart, and to help prevent future problems. You may need to have a procedure like:

angioplasty and stent implantation
bypass surgery (also known as coronary artery bypass grafts or CABG).
Read more about heart procedures and devices

Preventing further problems
Medical treatments and healthy lifestyle choices can help your heart attack recovery, greatly reduce your risk of further heart problems, and relieve or control symptoms such as angina. Read about living with heart disease

Cardiac rehabilitation
If you’ve had a heart attack or a procedure, you should be given information about a cardiac rehabilitation program which is another really important step in your recovery.

What is Valvular Heart Disease?
Valvular heart disease is characterized by damage to or a defect in one of the four heart valves: the mitral, aortic, tricuspid or pulmonary. The mitral and tricuspid valves control the flow of blood between the atria and the ventricles (the upper and lower chambers of the heart). The pulmonary valve controls the flow of blood from the heart to the lungs, and the aortic valve governs blood flow between the heart and the aorta, and thereby the blood vessels to the rest of the body. The mitral and aortic valves are the ones most frequently affected by valvular heart disease.

Normally functioning valves ensure that blood flows with proper force in the proper direction at the proper time. In valvular heart disease, the valves become too narrow and hardened (stenotic) to open fully, or are unable to close completely (incompetent).

A stenotic valve forces blood to back up in the adjacent heart chamber. While an incompetent valve allows blood to leak back into the chamber it previously exited. To compensate for poor pumping action, the heart muscle enlarges and thickens, thereby losing elasticity and efficiency. In addition, in some cases, blood pooling in the chambers of the heart has a greater tendency to clot, increasing the risk of stroke or pulmonary embolism.

The severity of valvular heart disease varies. In mild cases there may be no symptoms, while in advanced cases, valvular heart disease may lead to congestive heart failure and other complications. Treatment depends upon the extent of the disease.

When to Call an Ambulance?
Call an ambulance if you experience severe chest pain.


When to Call Your Doctor?
Call your physician if you develop persistent shortness of breath, palpitations or dizziness.

What are the symptoms?
Valve disease symptoms can occur suddenly, depending upon how quickly the disease develops. If it advances slowly, then your heart may adjust and you may not notice the onset of any symptoms easily. Additionally, the severity of the symptoms does not necessarily correlate to the severity of the valve disease. That is, you could have no symptoms at all, but have severe valve disease. Conversely, severe symptoms could arise from even a small valve leak.
Many of the symptoms are similar to those associated with congestive heart failure, such as shortness of breath and wheezing after limited physical exertion and swelling of the feet, ankles, hands or abdomen (edema). Other symptoms include:
Palpitations, chest pain (may be mild)
Fatigue
Dizziness or fainting (with aortic stenosis)
Fever (with bacterial endocarditis)
Rapid weight gain

What are the causes?
There are many different types of valve disease; some types can be present at birth (congenital), while others may be acquired later in life.

Heart valve tissue may degenerate with age.
Rheumatic fever may cause valvular heart disease.
Bacterial endocarditis, an infection of the inner lining of the heart muscle and heart valves (endocardium), is a cause of valvular heart disease.
High blood pressure and atherosclerosis may damage the aortic valve.
A heart attack may damage the muscles that control the heart valves.
Other disorders such as carcinoid tumors, rheumatoid arthritis, systemic lupus erythematosus, or syphilis may damage one or more heart valves.
Methysergide, a medication used to treat migraine headaches, and some diet drugs may promote valvular heart disease.
Radiation therapy (used to treat cancer) may be associated with valvular heart disease.


What are the prevention steps?
Get prompt treatment for a sore throat that lasts longer than 48 hours, especially if accompanied by a fever. Timely administration of antibiotics may prevent the development of rheumatic fever which can cause valvular heart disease. A heart-healthy lifestyle is also advised to reduce the risks of high blood pressure, atherosclerosis and heart attack.
Don’t smoke.
Consume no more than two alcoholic beverages a day.
Eat a healthy, balanced diet low in salt and fat, exercise regularly and lose weight if you are overweight.
Adhere to a prescribed treatment program for other forms of heart disease.
If you are diabetic, maintain careful control of your blood sugar.

What is rheumatic heart disease?
Rheumatic heart disease describes a group of short-term (acute) and long-term (chronic) heart disorders that can occur
as a result of rheumatic fever. One common result of rheumatic fever is heart valve damage. This damage to the heart
valves may lead to a valve disorder.
Rheumatic fever
Rheumatic fever is an inflammatory disease that may affect many connective tissues of the body, especially those of the
heart, joints, brain or skin. It usually starts out as a strep throat (streptococcal) infection. Anyone can get an acute rheumatic
fever, but it usually occurs in children between the ages of 5 and 15 years. About 60% of people with rheumatic fever
develop some degree of subsequent heart disease.
Every part of the heart, including the outer sac (the pericardium), the inner lining (the endocardium) and the valves may be
damaged by inflammation caused by acute rheumatic fever. However, the most common form of rheumatic heart disease
affects the heart valves, particularly the mitral valve. It may take several years after an episode of rheumatic fever for valve
damage to develop or symptoms to appear.
Antibiotics can prevent streptococcal infection from developing into rheumatic fever. Any child with a persistent sore
throat should have a throat culture to check for strep infection. Penicillin or another antibiotic will usually prevent strep
throat from developing into rheumatic fever.
Symptoms
Symptoms of heart valve problems, which are often the result of rheumatic heart disease, can include chest pain,
excessive fatigue, heart palpitations (when the heart flutters or misses beats), a thumping sensation in the chest,
shortness of breath, and swollen ankles, wrists or stomach.
Treatment
If heart damage from rheumatic fever is identified in childhood or young adulthood, daily antibiotics may be required until
the age of 25 or 30, to help prevent recurrence of rheumatic fever and avoid the development of infective bacterial
endocarditis, an infection of the heart valves or lining of the heart. Additional treatment will depend on the type of heart
damage.

Overview
Heart disease describes a range of conditions that affect your heart. Diseases under the heart disease umbrella include blood vessel diseases, such as coronary artery disease; heart rhythm problems (arrhythmias); and heart defects you're born with (congenital heart defects), among others.

The term "heart disease" is often used interchangeably with the term "cardiovascular disease." Cardiovascular disease 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 those that affect your heart's muscle, valves or rhythm, also are considered forms of heart disease.

Many forms of heart disease can be prevented or treated with healthy lifestyle choices.

Symptoms
Heart disease symptoms depend on what type of heart disease you have.

Symptoms of heart disease in your blood vessels (atherosclerotic disease)
Cardiovascular disease symptoms may be different for men and women. For instance, men are more likely to have chest pain; women are more likely to have other symptoms along with chest discomfort, such as shortness of breath, nausea and extreme fatigue.

Symptoms can include:

Chest pain, chest tightness, chest pressure and chest discomfort (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
Pain in the neck, jaw, throat, upper abdomen or back
You might not be diagnosed with cardiovascular disease until you have a heart attack, angina, stroke or heart failure. It's important to watch for cardiovascular symptoms and discuss concerns with your doctor. Cardiovascular disease can sometimes be found early with regular evaluations.

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. Heart arrhythmia symptoms can include:

Fluttering in your chest
Racing heartbeat (tachycardia)
Slow heartbeat (bradycardia)
Chest pain or discomfort
Shortness of breath
Lightheadedness
Dizziness
Fainting (syncope) or near fainting
Heart disease symptoms caused by heart defects
Serious congenital heart defects — defects you're born with — usually become evident soon after birth. Heart defect symptoms in children could include:

Pale gray or blue skin color (cyanosis)
Swelling in the legs, abdomen or areas around the eyes
In an infant, shortness of breath during feedings, leading to poor weight gain
Less serious congenital heart defects are often not diagnosed until later in childhood or during adulthood. Signs and symptoms of congenital heart defects that usually aren't immediately life-threatening include:

Easily getting short of breath during exercise or activity
Easily tiring during exercise or activity
Swelling in the hands, ankles or feet
Heart disease symptoms caused by weak heart muscle (dilated cardiomyopathy)
In early stages of cardiomyopathy, you may have no symptoms. As the condition worsens, symptoms may include:

Breathlessness with exertion or at rest
Swelling of the legs, ankles and feet
Fatigue
Irregular heartbeats that feel rapid, pounding or fluttering
Dizziness, lightheadedness and fainting
Heart disease symptoms caused by heart infections
Endocarditis is an infection that affects the inner membrane that separates the chambers and valves of the heart (endocardium). 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
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 detected early, so talk to your doctor about your concerns regarding your heart health. If you're concerned about developing heart disease, talk to your doctor about steps you can take to reduce your heart disease risk. This is especially important if you have a family history of heart disease.

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

Causes
How the heart works
Your heart is a pump. It's a muscular organ about the size of your fist, situated slightly left of center in your chest. Your heart is divided into the right and the left side. The division prevents 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, comprising 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. 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 pumps blood through the aorta to supply tissues throughout the body with oxygen and nutrients.
Heart valves
Four valves within your heart keep your blood moving the right way by opening only one way and only when they need to. To function properly, the valve must be formed properly, must open all the way and must close tightly so there's no leakage. The four valves are:

Tricuspid
Mitral
Pulmonary
Aortic
Heartbeats
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).
Electrical system
Your heart's electrical wiring keeps it beating, which controls the continuous exchange of oxygen-rich blood with oxygen-poor blood. This exchange keeps you alive.

Electrical impulses begin high in the right atrium and travel through specialized pathways to the ventricles, delivering the signal for the heart to pump.
The conduction system keeps your heart beating in a coordinated and normal rhythm, which keeps blood circulating.
Various heart disease causes
The causes of heart disease vary by type of heart disease.

Causes of cardiovascular disease
While cardiovascular disease can refer to different heart or blood vessel problems, the term is often used to mean damage to your heart or blood vessels by atherosclerosis (ath-ur-o-skluh-ROE-sis), a buildup of fatty plaques in your arteries. Plaque buildup thickens and stiffens artery walls, which can inhibit blood flow through your arteries to your organs and tissues.

Atherosclerosis is also the most common cause of cardiovascular disease. It can be caused by correctable problems, such as an unhealthy diet, lack of exercise, being overweight and smoking.

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
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 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 congenital heart defects
Congenital 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 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 cause of cardiomyopathy, a thickening or enlarging of the heart muscle, may depend on the type:

Dilated cardiomyopathy. The cause of this most common type of cardiomyopathy often is unknown. It may be caused by reduced blood flow to the heart (ischemic heart disease) resulting from damage after a heart attack, infections, toxins and certain drugs. It may also be inherited from a parent. It usually enlarges (dilates) the left ventricle.
Hypertrophic cardiomyopathy. This type, in which the heart muscle becomes abnormally thick, usually is inherited. It can also develop over time because of high blood pressure or aging.
Restrictive cardiomyopathy. This least common type of cardiomyopathy, which causes the heart muscle to become rigid and less elastic, can occur for no known reason. Or it may be caused by diseases, such as connective tissue disorders, excessive iron buildup in your body (hemochromatosis), the buildup of abnormal proteins (amyloidosis) or by some cancer treatments.
Causes of heart infection
A heart infection, such as endocarditis, is caused when an irritant, such as a bacterium, virus or chemical, reaches your heart muscle. The most common causes of heart infection include:

Bacteria
Viruses
Parasites
Causes of valvular heart disease
There are many causes of diseases of your heart valves. You may be born with valvular disease, or the valves may be damaged by conditions such as:

Rheumatic fever
Infections (infectious endocarditis)
Connective tissue disorders
Risk factors
Risk factors for developing heart disease include:

Age. Aging increases your risk of damaged and narrowed arteries and weakened or thickened heart muscle.
Sex. Men are generally at greater risk of heart disease. However, women's risk increases after menopause.
Family history. A family history of heart disease increases your risk of coronary artery disease, especially if a parent developed it at an early age (before age 55 for a male relative, such as your brother or father, and 65 for a female relative, such as your mother or sister).
Smoking. Nicotine constricts your blood vessels, and carbon monoxide can damage their inner lining, making them more susceptible to atherosclerosis. Heart attacks are more common in smokers than in nonsmokers.
Certain chemotherapy drugs and radiation therapy for cancer. Some chemotherapy drugs and radiation therapies may increase the risk of cardiovascular disease.
Poor diet. A diet that's high in fat, salt, sugar and cholesterol can contribute to the development of heart disease.
High blood pressure. Uncontrolled high blood pressure can result in hardening and thickening of your arteries, narrowing the vessels through which blood flows.
High blood cholesterol levels. High levels of cholesterol in your blood can increase the risk of formation of plaques and atherosclerosis.
Diabetes. Diabetes increases your risk of heart disease. Both conditions share similar risk factors, such as obesity and high blood pressure.
Obesity.

Overview
Congenital adrenal hyperplasia (CAH) is a group of inherited genetic disorders that affect the adrenal glands, a pair of walnut-sized organs above your kidneys. A person with CAH lacks one of the enzymes the adrenal glands use to produce hormones that help regulate metabolism, the immune system, blood pressure and other essential functions.

CAH affects the production of one or more of three steroid hormones: cortisol, which regulates your body's response to illness or stress; mineralocorticoids, such as aldosterone, which regulate sodium and potassium levels; or androgens, such as testosterone, which are sex hormones. In many cases, CAH results in lack of cortisol and overproduction of androgen.

The milder and more common form of CAH is called nonclassic. The classic form, which is more severe, can be detected in newborn screening programs. Some forms of CAH can cause problems with normal growth and development in children and even be life-threatening.

Although there is no cure, with proper treatment, most people with congenital adrenal hyperplasia can lead normal lives.

Symptoms
Signs and symptoms of congenital adrenal hyperplasia vary, depending on which gene is defective and the level of enzyme deficiency.

There are two major types of congenital adrenal hyperplasia:

Classic CAH. This more-severe form of the disease is usually detected in infancy.
Nonclassic CAH. This milder and more common form may not become evident until childhood or early adulthood.
Classic CAH
Approximately two-thirds of people with classic CAH are classified as having the salt-losing form, while one-third have the simple-virilizing form. In both forms, affected females have genital ambiguity.

A child with classic CAH may experience:

A lack in the production of cortisol in both the salt-losing and simple-virilizing forms. Most of the problems caused by classic CAH are related to a lack of cortisol, which plays an important role in regulating your blood pressure, maintaining blood sugar and energy levels, and protecting your body against stress.
A lack in the production of aldosterone in the salt-losing form. This can lead to low blood pressure, a lower sodium level and a higher potassium level. Sodium and potassium normally work together to help maintain the right balance of fluids in your body.
Excess production of the male sex hormones (androgens such as testosterone). This can result in short height, early puberty and in females, abnormal genital development while in the womb.
Signs and symptoms of classic CAH in infants include:

In females, enlarged clitoris or genitals that look more male than female (ambiguous genitalia) at birth, but males have normal appearing genitals
Significant illness related to a lack of cortisol, aldosterone or both (adrenal crisis), which can be life-threatening
Signs and symptoms of classic CAH in children and adults include:

Very early appearance of pubic hair
Rapid growth during childhood, but shorter than average final height
Nonclassic CAH
This form of CAH is milder than classic CAH. Often there are no symptoms at birth. The condition is not identified on routine infant blood screening and often only becomes evident in late childhood or early adulthood. Hormone deficiency may only involve cortisol levels.

Although teenage and adult females may have normal appearing genitals at birth, later signs and symptoms often include:

Irregular or absent menstrual periods
Masculine characteristics such as facial hair, excessive body hair and a deepening voice
Severe acne
In both females and males, signs and symptoms of nonclassic CAH also may include:

Early appearance of pubic hair
Rapid growth during childhood, but shorter than average final height
When to see a doctor
Classic CAH is usually detected at birth through required newborn screening or when female babies show ambiguous genitalia. CAH may also be identified when male or female babies show signs of severe illness due to low levels of cortisol, aldosterone or both.

In nonclassic CAH, you may notice signs and symptoms of early puberty in your toddler or child. In this case, or if you have concerns about your child's growth or development, make an appointment with your child's pediatrician.

If you're pregnant and may be at risk of CAH because of your own medical history or your ethnicity, ask your doctor about genetic counseling.

Causes
In 95 percent of cases, the enzyme lacking in congenital adrenal hyperplasia is 21-hydroxylase. CAH may sometimes be called 21-hydroxylase deficiency. There are other much rarer enzyme deficiencies that also cause CAH.

CAH is passed along in an inheritance pattern called autosomal recessive. Children who have the condition have two parents who either have CAH themselves or who are both carriers of the genetic mutation that causes the condition.

Risk factors
Factors that increase the risk of having congenital adrenal hyperplasia include:

Parents who both have CAH or are both carriers of the genetic defect for the disorder
People in certain ethnic groups, particularly Ashkenazi Jews, but also Hispanics, Italians, Yugoslavians and Yupik Inuits
Complications
Complications depend on the type of congenital adrenal hyperplasia and its severity.

People with classic CAH are at risk of experiencing adrenal crisis. This is caused by severely low levels of cortisol in the blood, resulting in diarrhea, vomiting, dehydration, low blood sugar levels and shock. It's a life-threatening medical emergency that requires immediate treatment. Impaired production of aldosterone may occur as well, leading to dehydration with low sodium and high potassium levels. Adrenal crisis does not occur in the nonclassic form of CAH.

In classic and nonclassic CAH, males and females may eventually experience fertility problems.

Prevention
There is no known way to prevent congenital adrenal hyperplasia. Your doctors may recommend genetic counseling if you're thinking of starting a family and you're at risk of having a child with CAH.