News Release

Polynesian men at risk of sudden unexplained deaths

American Heart Association meeting report

Peer-Reviewed Publication

American Heart Association

HONOLULU, June 9 – Mention Lai Thai to a native Thai man and you may to see fear in his eyes. It is the phrase for sudden unexplained death syndrome, or SUDS – an inherited disorder that mainly strikes men of Southeast Asia, ages 40 to 60, while they sleep. Women are rarely affected, so Thai males in some rural villages sleep in ladies' nightclothes to ward off the ghost they believe may take their life.

There's no reality to that belief, but SUDS itself is all too real. It's caused by a well-known condition called ventricular fibrillation in which the heart's electrical activity is out-of-synch, preventing the heart from pumping enough blood to the body. And now, for the first time, SUDS has been detected in French Polynesia men, researchers reported today at the American Heart Association's Second Asia Pacific Scientific Forum.

"Although SUDS had never been reported in French Polynesia before, we hypothesized that it must be present because Polynesians migrated from Southeast Asia 2,000 to 5,000 years ago," says Joel Kamblock, M.D., lead author of the study. To test the theory, Kamblock and colleagues studied about 150 French Polynesians from 1999–2003 who they suspected could have SUDS. Some were admitted to the hospital after fainting, a known risk factor for SUDS.

Others had been admitted for cardiac arrest, a condition in which the heart suddenly fails without warning. Still others had abnormal results on an electrocardiogram (EKG), a test that measures the heart's electrical activity. All the patients were given another EKG after they entered the study. A specific pattern indicative of SUDS was seen in 32 of them, says Kamblock, a cardiologist at Centre de Cardiologie du Taaone in Papeete, French Polynesia.

About 70 percent of the 32 patients reported that an older male relative had unexpectedly died during the night, and about 60 percent of the patients had fainted in the past, he says.

More sophisticated electrophysiology testing confirmed the diagnosis in six of 11 patients. In that test, a catheter is placed in the right ventricle and the heart is stimulated by electrical impulses. "If we can induce ventricular fibrillation, most would agree these patients are at high risk of spontaneous ventricular fibrillation and SUDS," Kamblock explains.

"The message to give our patients is that men who have a family history of unexpected death and who have fainted should see their doctor for testing," Kamblock says. Studies in Southeast Asian countries have shown that a man with a family history who faints just one time has a 50 percent chance of dying of SUDS in the next five years. Fortunately, treatment is available in the form of an implantable defibrillator that zaps the heart, allowing it to resume normal pumping, Kamblock says.

Noting that the study was very small, Kamblock says his team will continue to study French Polynesians to try to find out the true incidence of SUDS in the country. Also, Kamblock and his colleagues have begun a randomized trial to determine if defibrillators would help prevent sudden death in high-risk patients who have no symptoms.

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Co-authors are Pascal Jarno, M.D.; Tristan Gillet, M.D.; Gerad Papouin, M.D.; Mark Schwab, M.D. and Koonlawee Nademanee, M.D.

NR03-1077 (AP/Kamblock)
Abstract P94 (Contains updated numbers from abstract)


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