WOMEN with breast cancer are known to have heart problems related to treatment, and now a new study shows their odds of developing an abnormal heart rhythm known as atrial fibrillation (a-fib) may increase in the wake of a breast cancer diagnosis.

Women who develop a-fib within a month of a breast cancer diagnosis are more likely to die from heart- or blood vessel-related problems within a year, the new research suggests.

A-fib occurs when the upper chambers of the heart quiver chaotically, causing a fast and irregular heartbeat. Symptoms may include heart palpitations, breathlessness, dizziness, and/or extreme fatigue. When left undiagnosed or untreated, a-fib dramatically raises the risk for stroke and heart failure.

Exactly why these two conditions travel together is not fully understood yet.

“Traditional risk factors such as age, cardiovascular risk factors remain risk factors for a-fib after a breast cancer diagnosis,” said study author Dr. Avirup Guha, an assistant professor of medicine at Case Western Reserve University in Cleveland. But “surgery, chemotherapy, inflammation and imbalances in the body’s normal processes caused by the cancer may be implicated,” he said.

Stress can also contribute to a-fib, and the emotional stress that often accompanies a new breast cancer diagnosis may play a role, but the researchers didn’t look at stress in this study.

For the study, the researchers analyzed data on more than 85,000 women aged 66 or older who were diagnosed with breast cancer between 2007 and 2014. These women, along with their cancer-free counterparts, were followed for one year to see who developed a-fib.

The incidence of women with breast cancer who developed new-onset a-fib was 3.9 percent, and this risk peaked in the two months following their diagnosis. By contrast, just 1.8 percent of women without breast cancer developed a-fib during one year of follow-up.

Women with more advanced breast cancer had a higher risk for developing a-fib, regardless of their treatment plan, the study showed.

A-fib was also more common in women who underwent complex surgeries such as a mastectomy.

There was no increased risk of dying within one year of breast cancer diagnosis for women in the study who had a-fib first, possibly because they were already seeing a cardiologist, Guha noted.

More research is needed to determine if prescribing heart medication to all new breast cancer patients can reduce the risk of a-fib and death, and/or if all people with newly diagnosed breast cancer should be monitored to rule out this dangerous heart rhythm.

(SD-Agencies)