Written by Dr. Gretchen Wells, director of the Women’s Heart Health Program at the UK Gill Heart & Vascular Institute.
Today’s technology has made tremendous strides in the diagnosis and treatment of heart disease, but until recently it was tricky to diagnose a heart condition called Microvascular Coronary Dysfunction (MCD).
The most common type of heart disease is caused by plaques that begin to clog one or more of the large arteries that carry blood to the heart. When the heart gets too little blood to meet its needs, people have chest pain (called angina). If blood flow is restricted even further – usually due to a clot that lodges in the narrowed artery – a heart attack and death may occur.
Plaque is often involved in MCD, too. But instead of accumulating in the larger coronary arteries, MCD occurs when the tiny blood vessels that branch off from the larger coronary arteries are blocked or damaged.
For unknown reasons, MCD occurs more frequently in women. In fact, it’s estimated that almost 50 percent of women who have persistent chest pain and low blood flow to the heart but no blockage of major arteries have undiagnosed MCD.
Unfortunately, standard tests for heart disease, such as stress tests and cardiac catheterizations, aren’t designed to detect MCD. These tests look for blockages in the large coronary arteries, but MCD affects the tiny coronary arteries. That means that you can have a cardiac catheterization that finds no blockages yet still be at high risk for a heart attack.
Sadly, people who have been reassured that “everything was OK” because their cardiac catheterization was clear might not feel the need to make lifestyle changes that would reduce their coronary risk and/or ignore warning signs that a heart attack is imminent.
If you have persistent chest pain, see a doctor right away. Your doctor may give you a stress test, which compares coronary circulation while you are at rest with your circulation during exercise. He or she may also recommend a cardiac catheterization, which involves threading a long thin tube from a small incision in your groin, neck or arm up into the heart to look for blockages in your arteries.
If your catheterization shows no sign of blockages and you are still experiencing chest pain, ask for a coronary reactivity test which can identify blockages in the smaller coronary arteries – the hallmarks of MCD. Available at specialized centers around the U.S., coronary reactivity testing is the gold standard for diagnosing coronary microvascular disease.
And always, if you experience severe chest pain, if that pain radiates down your arm or to your back or jaw, and/or you are short of breath, call 911 right away.