FACTBOX-Heart attacks often first symptom of heart disease

(Reuters) - Heart attacks are often the first hint that someone has heart disease and they are often fatal the first time.

Here are a few facts about heart attacks and heart disease:

-- Heart disease is the No. 1 killer of men and women in the United States and in most industrialized countries.

-- Nearly 700,000 people die of heart disease in the United States each year, 29 percent of all deaths, according to the U.S. Centers for Disease Control and Prevention.

-- According to the World Health Organization, heart disease, stroke and diabetes accounted for 32 percent of all deaths globally in 2005.

-- A heart attack is also called a myocardial infarction, and is caused when the blood supply to the heart is blocked. A blood clot can do this, or arteries can become blocked by a messy buildup of hardened fat called plaque.

-- More than 1.1 million Americans have a heart attack each year, two-thirds of them men. Almost all of them have heart disease.

-- Symptoms can be as subtle as nausea, or as dramatic as immediate unconsciousness. While the classic symptom is chest pain or pain in the left arm, often signs are not so clear.

-- Smoking is the main cause of heart disease. Poor diet and a lack of exercise are other causes and research is increasingly showing that even what people in developed countries consider to be a healthy diet contains too much fat and lacks enough fiber to prevent heart disease.

(Reporting by Maggie Fox; editing by Julie Steenhuysen)