New Guidelines on Frequent Cause of Sudden Death in Athletes

Nov. 8, 2011 -- When an athlete dies suddenly on the court or playing field, often an undiagnosed heart condition called hypertrophic cardiomyopathy is the cause.

Now new guidelines aim to shine a light on the diagnosis and treatment of hypertrophic cardiomyopathy (HCM), a disorder that affects an estimated 600,000 Americans.

"It is an important cause of sudden cardiac death during competitive sport, and from that standpoint perhaps is brought to the headlines more frequently,"says Bernard J. Gersh, MD, PhD, who co-chaired the committee that wrote the new guidelines.

"It’s one of the commonest inherited cardiac diseases, and it probably hasn’t had the attention it’s deserved. I think if you talk to people out there there’s a great deal of confusion about how to treat this condition," says Gersh, who is a professor of medicine at the Mayo Clinic in Rochester, Minn.

New Focus on Hypertrophic Cardiomyopathy

In HCM, the muscular walls of the heart thicken abnormally, making it harder for the lower chambers to fill and pump blood.

Misaligned muscle fibers can also cause electrical abnormalities that can cause heart rhythm problems.

"Those electrical abnormalities can cause someone to drop dead," says Tara Narula, MD, a cardiologist at Lenox Hill Hospital in New York City.

Symptoms of the condition may include chest pain, shortness of breath, fainting and dizziness during exercise, heart palpitations, high blood pressure, and rarely, heart failure.

In many cases, though, there may be no warning signs, and the condition is discovered during an autopsy.

A Way to Move Forward

Doctors want people to know that having HCM isn’t a death sentence. In fact, most people with the condition will have a normal life span.

"This disease, once, not that long ago, regarded as mysterious and almost universally associated with poor outcomes is now a highly treatable genetic heart disease,” says Barry Maron, MD, director of the Hypertrophic Cardiomyopathy Center at the Minneapolis Heart Institute Foundation. Maron co-chaired the committee that developed the recommendations.

The guidelines are jointly published by the American Heart Association and the American College of Cardiology Foundation. They are published in the journal Circulation.

Among the key recommendations:

• Although people with hypertrophic cardiomyopathy should not participate in intense or competitive sports, low-intensity aerobic activities like golf or hiking can be a reasonable part of a healthy lifestyle.
• Because HCM is often inherited, all first-degree relatives of someone known to have the disorder should be screened.
• Children of parents with HCM should continue to be tested every 12 to 18 months since the disease may only present itself later in life.
• Patients should be offered genetic testing and counseling.
• All patients with hypertrophic cardiomyopathy should be evaluated for the risk of sudden death.
• Patients judged to be at high risk should be offered implantable defibrillators to prevent sudden death.
• Drug therapy can help control symptoms like shortness of breath and chest pain.
• Cardiac magnetic resonance imaging can be used to diagnose HCM when electrical tests and ultrasounds are inconclusive.
• When symptoms are severe and not helped by medications, surgeries to remove muscle from the heart wall can help.
• These surgeries should be performed by doctors who have performed at least 20 similar procedures or at a center dedicated to the treatment of HCM.

Cardiologists welcomed the new guidelines, saying they would improve the care of people with HCM.

"This can only be helpful. The fact that this is laying out very clearly not only what drugs are good but how to screen for it, that patients should be genetically counseled -- all of the different aspects --  they really are pinning down" what should be targeted by a cardiologist, Narula says.