Something strange and ominous is happening to young people, especially women but also to lesser numbers of men. They are dying of sudden heart attacks (acute myocardial infarction, AMI) without the classic symptoms of heart disease, chest pain or blocked arteries. They die quickly, as though struck by lightning.

Every year since accounting began, there has been a tiny number of persons in the U.S. who died abruptly for no apparent reason. In fact, the annual list of mortality statistics issued by the U.S. National Center for Health Statistics included "unknown cause' as a category, along with heart disease, cancer, stroke, and so on, until about 10 years ago. It was about that time that I called a statistician at NCHS to ask if the number dying for unknown reasons was going up. His answer was a definite and frustrated "Yes!' 

Federal biostatisticians go to considerable lengths to determine a cause for every death on U.S. soil. People are simply not allowed to die without a good reason. And yet, despite their best efforts, there was a rising number of deaths that no one could account for.

NCHS appears to have solved the problem and now everyone who dies can be placed in an acceptable category. Since each death involves a heart that stops beating, deaths for "unknown' reasons have become deaths from "heart attacks.'

A recent article in the Journal of the American Medical Association sounded an alarm and made the evening news: increases in the number of heart attack deaths between 1996 and 2004, occurring in young, healthy and symptom-free women has shocked the medical community.  Deaths from "unknown causes' remain and now happen often enough to have the attention of physicians, researchers and the government.

In the dry but riveting language of a medical journal:

The risk among  [young] women relative to men " is not " explained by differences in MI severity, comorbidity, or treatment. ".
The reasons for this age-dependent disparity in mortality [for younger women] are not clear.

Translation: We haven't a clue what is going on.

The statistics include only those who die of sudden heart attack in the hospital. Abrupt cardiac failure also happens to men and women who die outside of the hospital and to unknown numbers who look sudden death in the face but survive.   It occurs to those with heart disease, high blood pressure, obesity or diabetes, and the elderly, and those 'contributing factors' are blamed for the death even when they are not responsible.  According to NCHS, death certificates listing Acute Myocardial Infarction as the primary cause actually occur almost 30% more often than officially tabulated.

The total incidence of sudden death that can be attributed to nothing beyond heart failure is a complete mystery. The young and symptom-free may be the tip of the iceberg.   

The occurrence of acute myocardial infarction among the young and even the very young, was first documented in 2001. The CDC cited an increase of 281 deaths, or 30%, to women ages 15 to 34 between 1989 and 1996.  Fifty-six of those were younger than 25.

By 2008 the American Heart Association reported  that "heart disease' kills about 16,000 young women annually and accounts for 40,000 hospitalizations in young women.

And in 2009 the Archives in Internal Medicine reported that

roughly 9,000 American women under age 45 have heart attacks each  year"

In a just over a decade, the inconceivable had become common place.

Parallel to the rise in sudden, symptom-free, death, other things were happening in the 1990's.