Heart failure can occur during pregnancy, and Black women fare worse than others. Penn doctors are starting to find out why.

For several days, Carmelita Murphy felt short of breath and her legs were swollen. She had given birth to a son, DJ, just two weeks earlier, so she figured those symptoms were part of the deal.

Then came the really bad headache. After promising her mother that she would get it checked out, she went to bed that night in her Atlantic City apartment. But at 1 a.m., when she heard the baby cry and tried to get up, she felt dizzy and passed out.

Murphy, then just 20 years old, had a condition normally seen in people many decades older: heart failure.

Somehow the demands of pregnancy proved too great for her heart to handle, and the organ had become weak and stretched out, able to pump just a fraction of the blood her body needed. To make matters worse, blood clots formed in her heart, and one traveled to her brain. She had suffered a stroke, and was airlifted to the Hospital of the University of Pennsylvania.

This type of pregnancy-related heart failure, called peripartum cardiomyopathy, is uncommon, though it may be on the rise due to women having children at an older age. By some estimates, it now occurs in 1 out of 1,000 pregnancies, typically during the last month of pregnancy or within a few months after delivery. In most cases, the complications are milder than Murphy’s, and with proper treatment, the heart’s pumping ability often returns to near normal.

Yet the underlying cause remains something of a mystery, and it’s unclear why some patients — in particular, Black women such as Murphy — fare much worse than others. Black women are more likely than white women to develop the condition, less likely to regain normal heart function, and twice as likely to die from the disease.

New clues have emerged in recent research, including several studies at Penn’s Perelman School of Medicine. Socioeconomic disparity, rooted in long-standing systemic racism, appears to play a role. Some patients have genetic mutations that raise the risk of developing the disease. And two other health issues, preeclampsia and obesity, are associated with a higher risk of this deterioration in heart function.

But in most cases, the heart condition comes on without warning. Murphy was trim and in apparent good health, with no significant history of heart disease in her family.

She received high-level care, first undergoing a procedure to have the clot removed from her brain, followed by surgery to implant a heart pump in her abdomen.

Yet more than two years later, she is still recovering. The pump has been removed and her heart function has largely recovered, but because of the stroke, she walks with a limp, sometimes struggles to remember things, and has trouble using her right hand. Her dream of going to dental school is on hold.

Murphy wonders: Is there some way it all could have been prevented? And if not for baby DJ’s cries in the middle of the night, she thinks, it would have been even worse:

“He’s the one that saved my life.”

The human heart pumps more than two billion times in a typical lifetime, and a lot of things have to go right with each beat. A key player is a long, elastic protein called titin, which squeezes and relaxes with each contraction of muscle, said Penn cardiologist Zoltan P. Arany.

“It’s like a rubber band,” he said.

But in some people, a genetic mutation causes that protein to be truncated. The result seems to be that the rubber band cannot squeeze as well, Arany said.

People with the mutation do not automatically develop heart failure. But if such a person is subjected to an additional “insult” — such as chemotherapy, alcohol abuse, or age-related decline — the combination can overtax the heart, weakening the muscle so it can no longer keep up, he said.

And, according to a recent study by Arany and colleagues published in the journal Circulation, another such insult is pregnancy. In a group of 469 women with peripartum cardiomyopathy, 10.4% had truncated versions of the titin protein — about 10 times as often as the mutation occurs in the general population. In an additional 2% to 3% of patients, the researchers identified mutated versions of three other heart-muscle proteins that seemed to play a role in the disease.

Is this genetic profile robust enough to predict which women are at risk? Not yet, Arany said. Plenty of women with these mutations do not develop heart failure, so testing everyone would result in unnecessary anxiety. For now, he said, it would make sense to test for these mutations only in the immediate family members of women with peripartum cardiomyopathy, to see whether they, too, might be prone to the disease.

And evidence suggests that additional, non-genetic factors contribute to heart failure during pregnancy, especially in Black women.

Black women are no more likely than others to carry genetic mutations that are thought to contribute to the disease, yet they are more likely to experience severe consequences. A key reason might be where they live. In another recent Penn study of 220 women who had the condition, worse outcomes in Black women were associated with living in more disadvantaged neighborhoods — as measured by a composite score of socioeconomic indicators such as unemployment, income, and the percentage of adults without a high school diploma.

Exactly how that mix of factors contributes to greater severity of illness is likely complicated, said Penn cardiologist Jennifer Lewey, one of the authors. Black women might have less access to specialty care, she said. Or perhaps some are less trusting of the health-care system due to unequal treatment, and feel less comfortable asking about their symptoms. Arany, another one of the authors, said physicians may need to improve their communication skills.

Racial disparity has long been a troubling trend for all types of maternal mortality, yet socioeconomic factors do not fully explain the gap. Black women with at least a college degree, for example, are nearly twice as likely to die of pregnancy-related complications as white women who have not earned a high school diploma.

Murphy, who now lives in Absecon, N.J., said she didn’t think race played a role in the severity of her disease. But she wonders whether a warning signal was missed.

Several days after DJ’s birth, when she and the baby were still at Shore Medical Center in Somers Point, she started to feel short of breath and worried she was having an anxiety attack. Doctors agreed that might be the case. But she soon felt a bit better, and she and the baby were sent home.

“I wish I would’ve known that meant something,” she said.

A week later came the crushing headache — in retrospect, likely a symptom of the stroke — followed by DJ’s cry in the middle of the night. His father, Denier Bond, saw that Murphy was slumped over, and called 911. An ambulance took her back to Shore Medical Center, where physicians realized she needed advanced treatment. She was transferred to AtlantiCare in Atlantic City, then flown by helicopter to Philadelphia. Her recovery took months.

Lewey, who helped take care of Murphy, agreed that the young woman’s shortness of breath may have been a warning sign. In the days before her stroke, the new mother also experienced swelling in her legs, another possible indicator of heart trouble.

But therein lies the challenge. Those symptoms — swelling and trouble breathing — are common in pregnancy. The last thing doctors want is for all expectant mothers to worry that their hearts are failing, as that complication occurs in just 1 out of 1,000 pregnancies, at most. That’s lower than a person’s lifetime chance of dying in a motor vehicle accident.

The time to worry is when these symptoms come on abruptly, or they are especially severe, Lewey said.

“It’s a sudden change, or a sudden worsening, where it may be difficult to walk across the room or up the stairs,” she said.

Andrea Cardwell, 44, can relate.

In 2015, in the final weeks before she delivered twins by C-section at Lankenau Medical Center, her legs were swollen and she had trouble breathing.

At first, she did not want to make too much of it. Cardwell is an intensive-care nurse at Bryn Mawr Hospital, and she thought that sometimes, her medical training led her to be overly anxious about her own health.

Yet she was a bone-cancer survivor, and had been through chemotherapy years earlier — a risk factor for heart trouble. And after the delivery, her symptoms grew suddenly worse. The first night at home, she looked forward to resting in her own bed while her husband, Tom, looked after the twins. But when she lay down, the opposite happened.

“I couldn’t breathe,” she said. “I was panicking and wheezing.”

That’s a classic sign of heart failure, when breathing difficulty becomes worse upon lying down. Cardwell went back to the hospital, and sure enough, she was diagnosed with peripartum cardiomyopathy. Tests revealed that just 20% of the blood in her left ventricle was being pumped out with each beat. (A normal “ejection fraction” ranges from 55% to 65%.)

Cardiologists brought Cardwell’s condition under control with medication. For several months, she also wore a battery-powered defibrillator vest, which would shock her heart into normal rhythm in the event it stopped beating. It never did. But more than five years later, she still gets winded more easily than before.

Murphy’s ejection fraction in the hospital was even lower — just 10%. Doctors implanted a pump called a left ventricular assist device (LVAD), and she eventually recovered to the point that they removed it.

She still feels the aftereffects of the stroke. A natural right-hander, she had to learn to write with her left hand, and more physical therapy lies ahead. But she is feeling optimistic.

“You can’t believe how bad it was from September 2018 compared to now,” she said.

And she feels fit enough to keep after DJ, now 2½. She plans to tell him, someday, how he saved her life.