While Zika is most closely linked to causing severe birth defects in babies born from mothers with the virus, new research that will be presented at the American College of Cardiology (ACC)’s 66th Annual Scientific Session beginning on March 17 provides evidence that the virus could have detrimental effects on the heart.

The research was led by Karina Gonzalez Carta, MD, a cardiologist and research fellow at the department of cardiovascular diseases at Mayo Clinic in Rochester, Minnesota. She will present her findings at the conference on Saturday, March 18, at 1:30 p.m. ET in Poster Hall C.

Her study, which is the first to report evidence that Zika is related to heart troubles, included nine adult patients with the virus who had no history of heart disease and were being treated at the Institute of Tropical Medicine in Caracas, Venezuela. Six of the patients were women, Carta said during a March 7 web briefing with reporters.

“You may wonder why the Mayo Clinic in Rochester, Minnesota is doing a study about Zika. ... Well I am a cardiologist currently working as a research fellow [there], but I am from Venezuela,” she said.

In the study, all but one patient developed arrhythmias, while two-thirds had evidence of heart failure. Though the results are alarming, they weren’t necessarily surprising because many mosquito-borne diseases are known to have adverse effects on the heart, Carta said.

In addition to dangerous arrhythmias among the patients, there were six cases of heart failure, three cases of atrial fibrillation, two cases of non-sustained atrial tachycardia and two cases of ventricular arrhythmias.

“Our report provides clear evidence that there is a relationship between the Zika virus infection and cardiovascular complications,” Carta said. “Based on these initial results, people need to be aware that if they travel to or live in a place with known Zika virus and develop a rash, fever or conjunctivitis, and within a short time frame also feel other symptoms such as fatigue, shortness of breath or their heart skipping beats, they should see their doctor.”

She said cardiovascular symptoms did not appear until 10 days after the patients had complained about Zika-related symptoms. So far, none of the patients have recovered from their cardiac problems, but symptoms have improved since they began treatment.

Carta’s study has shed light on an important facet of the Zika virus, which could help diagnose and treat many more people who are contracting it. Many people likely have cardiac conditions caused by Zika, Carta said.

“Awareness is key, not only for health providers and pregnant women, but for the general population of the world,” Carta said. “We need larger, systematic studies to understand the actual risk of Zika-related cardiac problems and what makes one patient more prone to develop them.”