The Heart of a Woman

David L. Katz, MD, MPH, FACPM, FACP

A more common symptom of dangerous heart disease in women is feeling deeply tired, even after sleeping well.

The heart of a woman is unique.  That may invoke thoughts of love and tenderness, of women from Venus and men from Mars.  But we are learning it should also invoke images of the coronary arteries, and urgent scenes in the coronary care unit.  Heart disease in women is unique.

We have long known that women develop heart disease on average 10 years later than men. Women are generally protected, at least relatively, from coronary heart disease until after menopause, although the reasons why are less clear than they seemed back in the days of prevailing enthusiasm for hormone replacement.  Men are generally considered at risk after age 45, women after age 55. 

There has also long been evidence that the symptoms of heart disease in women tend to be “atypical.”  This is in quotes because “typical” and “atypical” must be relative to something, and so the idea that women have unusual manifestations of heart disease highlights the view that the norms of heart disease are set by patterns in men. 

To some extent, the shorter life expectancies of previous generations masked the threat of heart disease in women, and diverted our attention from it, since heart disease develops later in women than men.  Compounding this problem was the historical tendency to enroll mostly, or exclusively, male populations into clinical trials.  We simply know more about heart disease in men than women.

 The classic sign of heart disease is angina pectoris, Latin for chest pain.  Men who develop clinically significant coronary artery disease generally have pain in the center of the chest, at times compounded by shortness of breath, nausea, or a cold sweat.

Women, too, may develop angina.  But a more common symptom of dangerous heart disease in women is feeling deeply tired, even after sleeping well.  Other common symptoms include breathlessness, insomnia, nausea, anxiety, back pain, belly pain, fainting, confusion, or even headache.

Results from a NIH-sponsored study called the Women's Ischemia Syndrome Evaluation (WISE) announced at a conference in January of this year are helping to explain the unique manifestations of heart disease in women. Whereas men often have a build-up of atherosclerotic plaque clearly visible on a coronary angiogram- an image of the heart’s blood vessels obtained by filling them with dye during a procedure called cardiac catheterization- women may not. In many women with symptoms of heart disease, plaque is distributed uniformly in tiny vessels and is all but invisible on angiogram.

This condition is referred to as “coronary microvascular syndrome.” Why plaque builds up differently in women than men is not yet well understood. But different patterns of heart disease call for different methods of evaluation. In a woman with symptoms of heart disease, a normal appearing angiogram does not reliably rule out imminent danger.

So what does?  A MRI scan of the coronary vessels can show plaque an angiogram won’t reveal.  Both CT scans and ultrasound tests may serve this purpose, too.  Such testing is not yet standard, although that may change as our understanding advances.  Another method for detecting microvascular plaque is called endothelial function testing. The endothelium is the inner lining of blood vessels, and the release of chemicals from endothelial cells controls the pattern of vessel constriction and dilation. An abnormal pattern is a good indicator of impending heart disease.  As of yet, however, this method is more a research tool than a standard diagnostic test.

Therefore, until we learn more and our diagnostic technologies advance, the best means of detecting dangerous heart disease in women is a high index of suspicion.  Both patient and health care professional alike should heed any hint of the condition, and err on the side of caution.

Heart disease is the leading cause of death in women as in men, and will shorten the lives of one in three- a toll ten times as great as that of breast cancer.  Studies such as WISE are narrowing our knowledge gap, and teaching us that a woman’s heart is unique in sickness, as in health.  If that means unique care is warranted, that should fast become the standard of medical practice.  Until it does, you’d best be prepared to look out for yourself.

Risk factors for heart disease are much the same in women as in men.  These include a history of the disease in close relatives (especially female relative), high blood pressure, a high level of LDL cholesterol, a low level of HDL cholesterol, high triglycerides, or diabetes.  Lifestyle factors such as physical inactivity, smoking, or a poor diet increase risk as well.  Obesity is a risk factor for heart disease especially when weight accumulates in the belly; a waist circumference of 34 inches or more in a woman indicates increased risk.

 These risk factors are all modifiable through behavioral choices, medication, or both.  One way to circumvent the diagnostic challenges of coronary disease in women is to prevent the disease outright.  Diligent attention to, and management of, these risk factors offers that promise.  Know your risk factors, and address them. 

But coronary disease may at times develop nonetheless.  Forewarned of its symptoms, women are forearmed to mitigate its dangers. If you are a woman with unexplained fatigue, breathlessness, or an inexplicable pain anywhere from your navel to your head, see your doctor.  If the usual tests don’t show heart disease, but there is no other good explanation, don’t stop with the usual tests.  Your safety is best protected if you and your doctor assume heart disease until proved otherwise. Demand nothing less.

David L. Katz, MD, MPH, FACPM, FACP; Prevention Research Center, Yale University School of Medicine: www.davidkatzmd.com

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