Posted on 07/08/2009

PITTSBURGH–Initially the reports stated that Michael Jackson died of cardiac arrest, but what killed him remains a mystery. Days later, television pitchman Billy Mays died of heart disease while asleep.

More than a year ago, NBC news commentator Tim Russert died from a cardiac arrest caused by heart disease.

All three deaths were unexpected in the two 50-year-olds and the 58-year-old Russert.

Celebrity deaths point to the impact of the nation's No. 1 killer: cardiovascular disease. It accounts for 35.3 percent of all deaths in the United States, or more than cancer, accidents and HIV/AIDS combined. In 2006, according to the Centers for Disease Control and Prevention, 631,636 people died of cardiovascular disease, down from 864,480 in 2005.

While deaths are declining, challenges remain, especially in trying to revive people after cardiac arrest.

The New England Journal of Medicine published a study recently that states that survival rates when cardiopulmonary resuscitation is used didn't improve from 1992 through 2005. The study focused on 433,985 elderly patients who had undergone in-hospital CPR, with about 18 percent surviving until they could be discharged from the hospital.

Odds of survival for African-American patients were nearly 24 percent lower than those of similar white patients, even though African Americans more often received CPR.

"The proportion of in-hospital deaths preceded by CPR increased, whereas the proportion of survivors discharged home after undergoing CPR decreased," the study says.

It highlights the puzzle that cardiac arrest still poses for the health-care system.

Cardiologists are using recent celebrity deaths to explain the difference between cardiac arrest and heart attack, which can overlap but represent different conditions affecting heart function.

"Ultimately every death that occurs comes with cardiac arrest," said Dr. Norman Abramson, a retired professor of emergency medicine at the University of Pittsburgh. "But it requires more specification."

Sudden cardiac arrest -- chaotic heart rhythms that can stop the heart in people without previous signs of illness or heart disease -- has been a focus in the Jackson case.

"What we're talking about when people have a cardiac arrest is a cardiac rhythm problem," said Dr. William Barrington, associate professor of medicine at the UPMC Cardiovascular Institute. "The rhythm becomes chaotic and doesn't pump blood efficiently." When blood pressure drops, the brain doesn't receive the needed profusion of blood.

"What that does is cause people to become unconscious, and if it happens for more than a few minutes, you start talking about irreparable brain damage, and as the heart begins to die you cannot recover cardiac function," Dr. Barrington said. "Generally if you treat it immediately, within the first minute or two, people do very well."

But brain damage occurs when the heart cannot be restarted in about four minutes. Jump-starting the heart is best done with defibrillation, an electrical shock that puts the heartbeat back into synchronization.

Dr. Abramson, a director on the board of the Sudden Cardiac Arrest Foundation based in Pittsburgh, described a heart attack, or myocardial infarction, as a plumbing problem caused by plaque buildup in arteries that restricts blood flow to the heart.

The result goes beyond heart-muscle damage. Too little oxygen also can cause acid buildup that can prompt erratic heartbeats and cardiac arrest.

"Commonly, when part of the heart muscle dies, the heart can beat irregularly or can't pump blood, so a heart attack can lead to a cardiac arrest," Dr. Abramson said. "Every heart attack does not lead to cardiac arrest, and every cardiac arrest is not caused by heart attack."

When cardiac arrest, rather than weakness or chest pain, is the initial symptom of a heart attack, the survival rate nationwide dips to about 2 percent, although the rate in Pittsburgh is 6 percent.

And 50 is not too young for heart disease. Doctors say they see patients with heart problems in their 40s. Young athletes can die of cardiac arrest due to heart disease or heart defects.

Problems other than arterial blockage can cause cardiac arrest, including legal or illicit drug use that adversely affects nerve function to the heart. Respiratory or pulmonary disease and electrolyte imbalances of minerals necessary for normal heart function also can precipitate cardiac arrest.

Cardiac arrest requires quick action to prevent death. More defibrillators, Dr. Abramson said, should be available at places where people exercise.

He said, "Our purpose is to educate the public and make them aware that sudden unexpected cardiac arrest can affect anyone at any age."

-David Templeton, Pittsburgh Post Gazette


http://www.post-gazette.com/pg/09189/982339-114.stm#ixzz0KfZsvnMj&D

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