In many ways, the fact that my cardiac treadmill stress test results appeared “normal” was not a surprise, despite my textbook heart attack symptoms of crushing chest pain, nausea, sweating and pain radiating down my left arm. What we now know is that single-vessel heart disease, which is more common in women than in men, may be less likely to be picked up at all on a treadmill test.
Even though my left anterior descending coronary artery was 95% blocked, this didn’t show up. Similarly, for other women non-obstructive heart disease (again, more common in women) is harder to identify given our existing diagnostics. Women are more likely to suffer from coronary microvascular disease affecting the smallest blood vessels of the heart. And spasm conditions like Prinzmetal’s variant angina are difficult to catch at the best of times, but women can be just as dead after a heart attack caused by undiagnosed Prinzmetal’s as they would be due to fully-occluded coronary arteries.
Here are just a few ways in which our hearts are different than men’s hearts:
ARTERIES: Women’s arteries have tiny openings – on average, 1.5 mm. Men’s arteries have openings of 2.5 mm. This difference makes some types of surgery much riskier for women. (When I attended a Mayo Clinic conference on women and heart disease in October 2015, I learned that early stents did not fit any female patients because the stents were too big).
In some women, arterial plaque builds up as an evenly spread layer along artery walls, which isn’t treatable using procedures such as angioplasty and stenting designed to flatten the bulky, irregular plaque in some men’s arteries. For some women, drug treatment — rather than angioplasty or stenting — may be a better option.
SIZE: A woman’s heart weighs 118 grams on average, about as much as a green pepper. A man’s heart weighs about 60 grams more. Larger hearts can be easier for cardiologists to work with, so when a woman receives a transplant, for example, it’s usually a man’s heart. Dr. Marianne Legato of Columbia University explains that not only do women have smaller hearts and smaller arteries, but their hearts also beat faster, even during sleep.
VALVES: Women’s valves are floppier than men’s, which may be why we’re born with more valve disorders, such as mitral valve prolapse, a condition that affects about 6% of women and can progress to the point where the valve between the upper and lower left chambers no longer closes properly and requires heart surgery for repair or replacement.
“What we’ve learned in heart surgery is that we have a 50% higher chance of letting women die during heart surgery, not because we don’t care or because we don’t try hard, but because women are different. Their hearts respond differently, their symptoms are different, their physical examination is different, and it all goes together.
“Frankly, heart surgery is the ultimate physical examination. We touch, we feel, we suture – and women are different!”
HEART FAILURE: Women and men tend to experience different types of heart failure – a functional disorder in which the heart cannot pump enough blood throughout the body. Women have a higher chance of diastolic dysfunction, which means their hearts become stiff and aren’t able to relax between beats. Men are more likely to suffer systolic dysfunction, which means their hearts become weak and floppy and have trouble pumping blood.
Experts believe this may contribute to women being under-diagnosed with heart problems because diastolic dysfunction is harder to detect. A study last year published in the American Journal of Clinical Cardiology found that heart failure also affects women at an older age and often with a stronger heart compared to men. This means that while women can live longer with the disease, they also tend to have lower quality of life than men due to greater physical limitations with exercise, more heart failure-related hospital stays and depression.
Cardiologist Dr. Sharonne Hayes, founder of the Mayo Women’s Heart Clinic, adds that the type of heart failure most commonly seen in women — known as heart failure with preserved ejection fraction — is caused by problems when the heart relaxes between beats, leading to elevated blood pressure that can cause the heart to stiffen. “But we don’t have a treatment for it. We need it, because it’s predominantly a female disease.”