According to the study’s lead author BWH’s Robert E. Eckart, D.O., they had expected that most of the sudden deaths would stem from structural heart abnormalities, but that in actuality, a large number of the deaths defied this theory and could not be identified by today’s screening methods. “The findings suggest genetic abnormalities that affect the heart’s electrical system are likely to be a significant cause of death.”
Researchers reviewed cases of 126 non-traumatic sudden deaths that occurred among 6.3 million military recruits, male and female, aged 18 to 35 years from 1977 through 2001. After examining medical records of the 126 cases, researchers found that most individuals did not suffer from structural abnormalities of the heart that might have shown up during physical examination or an echocardiogram. Instead, researchers found that 86 percent of the sudden deaths were related to exercise. In addition, researchers found after autopsy that while 51 percent of the deaths were caused by one of many potential cardiac abnormalities, the single leading cause of sudden death in this population was a structurally normal heart. The cardiac abnormalities identified most frequently included coronary artery abnormalities, followed by inflammation of the heart muscle and an enlarged muscular wall of the heart that can block normal blood flow during heavy exercise.