U.S. evangelist Jerry Falwell died at a Virginia hospital today at age 73 shortly after being found unconscious and without a pulse in his office, according to his personal physician, Dr. Carl Moore.

An official cause of death has not been released, but Falwell had a history of heart problems.

Falwell survived two serious health scares in early 2005. He was hospitalized for two weeks with what was described as a viral infection, and was hospitalized again a few weeks later after going into respiratory arrest. Later that year, doctors found a 70 percent blockage in an artery, which they opened with stents.

Falwell’s medical history leaves open the possibility that the founder of the Moral Majority Organization may have suffered a fatal heart attack.

Heart disease is in fact the number-one killer of both men and women in the United States. Half a million people die of it each year, and more than 12 million people with cardiac disease.

A number of factors can influence a person’s risk for heart disease, including heredity and lifestyle choices such as smoking, excessive drinking, history of diabetes and consuming a high fat diet.

Perhaps the first defense against a fatal heart attack is recognizing the risk factors. There are different ways a heart attack can prevent itself.

Number one is the silent heart attack. Here you don’t have major chest pain, you don’t have shoulder pains, you may have a little palpitation, but you’re not tired, you’re not fatigued, and you’re not dizzy. However, when you go in for a physical, the doctor finds that you have had a silent heart attack.

Number two is typical angina or chest pain. This is chest pain with chest pressure that doesn’t go away, and it is quite important for individuals with these symptoms to get themselves to hospital within 30 minutes.

Number three is the sudden heart attack. This occurs when you have a major, catastrophic obstruction in a main branch of the coronary artery, and a very large area of your heart is instantly void of any blood.

Even though the three presentations of heart attacks described here, the underlying theme is the same—they all involve chronic or acute coronary artery disease.

In other words, you don’t go around with a normal coronary artery one day and the next day develop a major clot. The heart attack may present itself differently in different people, but the cause is the same no matter how we experience the critical moment.

Stents Vs. Drugs

After suffering respiratory arrest in 2005, Falwell had a 70 percent blocked artery opened with stents. But a recent study found that stents used in angioplasty procedures work no better than using drugs to treat heart disease.

The study, authored by Dr. William Boden of Buffalo and featured in the New England Journal of Medicine in April, showed that angioplasty did not save lives or prevent heart attacks in non-emergency heart patients.

Why did angioplasty not help more?

It fixes only one blockage at a time whereas drugs affect all the arteries, experts said. Also, the clogs treated with angioplasty are not the really dangerous kind.

Assessing Your Risk

Researchers have long noted the importance of body shape in determining a person’s risk factors for heart disease. They talk about the apples versus the pears. The apples tend to store their access fat in their stomach and chest. The pears store it below the hips, in their thighs and buttocks.

A recent study found that a person’s waist-to-hip ratio is an even better predictor of cardiovascular risk than their body mass index, or BMI, the commonly used ratio of weight to height. It appears that a large waist size, which generally indicates large amounts of abdominal fat, is more harmful than a larger hip size.

Determine your body shape and risk for cardiovascular disease by calculating your waist-to-hip ratio. First, measure your waist at its smallest circumference; then, measure your hips at their widest. Next, divide your waist measurement by your hip measurement. For example, a person with a thirty-six-inch waist and forty-inch hips would have a waist-to-hip ratio of 0.9. Waist-to-hip ratios over 0.85 in women and over 0.9 in men are strongly associated with an increased risk for heart disease.

Know the Signs

Most heart attacks do not come on swiftly and cause immediate death. And the best chance for surval is getting medical attention immediately at the first sign of a heart attack. The American Heart Association lists the following as the symptoms of a possible heart attack:

Chest discomfort. Most heart attacks involve discomfort in the center of the chest that lasts more than a few minutes, or that goes away and comes back. It can feel like uncomfortable pressure, squeezing, fullness or pain.

Discomfort in other areas of the upper body. Symptoms can include pain or discomfort in one or both arms, the back, neck, jaw or stomach.

Shortness of breath. May occur with or without chest discomfort.

Other signs: These may include breaking out in a cold sweat, nausea or lightheadedness

Foxnews.com health writer Marrecca Fiore contributed to this report.

Click here to check out Dr. Manny's book The Check List (Harper Collins, 2007), from which this article was excerpted.

Dr. Manny Alvarez is the managing editor of health news at FOXNews.com, and is a regular medical contributor on the FOX News Channel. He is chairman of the Department of Obstetrics and Gynecology and Reproductive Science at Hackensack University Medical Center in New Jersey. Additionally, Alvarez is Adjunct Professor of Obstetrics and Gynecology at New York University School of Medicine in New York City.

Dr. Manny Alvarez serves as Fox News Channel's senior managing health editor. He also serves as chairman of the department of obstetrics/gynecology and reproductive science at Hackensack University Medical Center in New Jersey. Click here for more information on Dr. Manny's work with Hackensack University Medical Center. Visit AskDrManny.com for more.