A heart attack, or myocardial infarction, occurs when the supply of blood and oxygen to a part of the heart muscle becomes blocked. The blockage is caused by a combination of clot and cholesterol inside the blood vessel to the heart. The heart muscle requires a constant supply of fresh blood and oxygen to keep pumping blood to every part of the body. When this is abruptly cut off during a heart attack, the heart muscle begins to die. If the blocked heart artery is not treated and opened quickly, the affected part of the heart muscle dies and is permanently replaced by scar tissue, preventing it from functioning fully.

Heart attacks can lead to dangerous arrhythmias and heart failure, and can even result in sudden cardiac death.
  A majority of heart attack victims misinterpret his or her heart attack symptoms as being caused by something else.

Heart attack symptoms vary from person to person. Not every person will suffer the classic symptoms, but the majority of them would feel some discomfort. Some classic symptoms are:

Chest pain

*Heaviness, tightness, squeezing, or pressure
*Pain that is located in the left side of the chest but that may radiate to the left or right shoulder and arm, neck, jaw, teeth, ear, or back
*Pain that starts suddenly, while you're at rest or during exertion
*Chest discomfort that is constant and lasts for more than ten to fifteen minutes
*Chest discomfort that is hard to localise; it might be in the middle of the chest or "all over" the chest. Chest pain or pressure may be the only warning sign of a heart attack, but it's more likely you'll feel some associated symptoms such            as:

*Shortness of breath
*Difficulty in breathing
*Feeling cold/clammy
*Sweating
*Extreme weakness, fatigue, or exhaustion
*Nausea or vomiting
*Palpitations or fluttering in the chest
*Dizziness or light-headedness
*Women, diabetics, and the elderly often do not experience  any of the classic heart attack symptoms. Fatigue, palpitations, and vague chest pain may be the only warning signs.

Myths

*A heart attack only affects older people.

Vasu a 29-year-old man got up in the middle of the night and complained to his brother, who is a dentist, about a burning sensation in his chest. Thinking it to be due to acidity he was given an antacid syrup and later he went back to sleep never to wake up again.

Although the manifestations of coronary artery disease typically occur during the middle and later years of life, in today’s world even the young are not absolutely free of the risk of a heat attack. The roots of coronary artery disease lie in childhood. Using heart-healthy lifestyle measures not only will help you but also will enable you to set an example for your children and grandchildren.

*Since I am thin and I exercise, I am not at risk for a heart attack

It doesn't matter what shape you are or what shape you are in, you can still be at risk for heart disease. Even thin people who exercise can have a heart attack, which is another reason why it's so important to speak with your doctor about the disease even if you don't fit the typical profile.

*Heart attacks don't really affect women

Heart disease is an important cause of death in women older than 40, especially after menopause. There are some differences, though, in how heart disease affects men and women. For instance, women often get sick later in life than men and are less likely to suffer the classical symptoms associated with an heart attack.

*A low-fat diet is all I need for heart health

The fact is that there are some fats that are good for you, like the ones found in fish, nuts and avocados. What you want to avoid is trans fats. They are found in products like cookies and potato chips.

*Chest pain is a must during heart attack

While it is true that heart attacks often cause pain in the chest, it is not necessary. The classic symptoms of a heart attack include a heavy feeling in the chest that may be painful. The heaviness or pain may spread to the left arm, neck, or jaw. Patients often complain of shortness of breath. It's common for heart attack victims to simply feel a foreboding of doom. Another common complaint is burning in the chest mistaken as heartburn.

*If you're having chest pain, the best thing you can do is wait and see.

The longer the delay before treatment of a heart attack begins, the greater the potential heart damage. If you're having significant chest discomfort, shortness of breath, or any other symptoms that suggest a heart attack, call emergency services immediately so you can be transported to the emergency room.

*After you've had a heart attack, your life will move inexorably downhill.
If one pays attention to what he eats and becomes involved in a regular walking programme, one could continue to lead an active life. Most people are surprised to hear this. There is no reason whatsoever to give up after you've had a heart attack. Modern cardiac rehabilitation can help people who've suffered a heart attack or have other serious forms of heart disease to live full, vigorous lives for many years after they experience the first manifestations of heart disease.

Immediate help

How you react to heart attack symptoms is just as important as recognising them. If you have any of the above symptoms or even consider that you might be having a heart attack, you need to act immediately. Fear, hesitation, and doubt lead to fatal delays in treatment.

*Stop what you are doing and lie down.
*Don't panic.
*Direct someone to call for an emergency ambulance service.
*If available take a tablet of aspirin dissolved in a glass of water.
*If one is available, place a sorbitrate tablet under your tongue.

A heart attack is a life-threatening medical emergency that must be recognised as soon as symptoms develop. Delays in treating heart attacks can lead to congestive heart failure, dangerous cardiac arrhythmias  and sudden cardiac death.

The author is a senior consultant and interventional cardiologist, Apollo Hospitals, Bangalore.