Researchers sound alarm over Zika's potentially harmful heart effects

March 9, 2017

As the Zika virus continues to spread globally, new evidence has emerged about the virus's potentially detrimental effects on the heart, according to data scheduled for presentation at the American College of Cardiology's 66th Annual Scientific Session.

The study—the first to report Zika-related heart troubles following infection—included adult patients with no prior history of cardiovascular disease who were treated at the Institute of Tropical Medicine in Caracas, Venezuela, one of the epicenters of the Zika virus outbreak. All but one patient developed a dangerous heart rhythm problem and two-thirds had evidence of heart failure, a condition in which the heart can't pump enough blood to meet the body's needs.

"Our report provides clear evidence that there is a relationship between the Zika virus infection and ," said Karina Gonzalez Carta, MD, cardiologist and research fellow at the department of cardiovascular diseases at Mayo Clinic and the study's lead author. "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 timeframe also feel other symptoms such as fatigue, shortness of breath or their heart skipping beats, they should see their doctor."

Carta and her team were not entirely surprised by their findings as they follow trends seen with other mosquito-borne diseases known to affect the heart, including the dengue and Chikungunya viruses. However, she noted that the burden and severity of heart problems, including rapidly progressive heart failure and potentially life-threatening arrhythmias, among these patients was unexpected.

Nine patients who were seen in the clinic in Caracas within one week of having Zika-type symptoms and who subsequently reported common symptoms of heart problems, most commonly palpitations followed by shortness of breath and fatigue, were included in this small, prospective case report. Only one patient had any previous cardiovascular problems (well-controlled high blood pressure), and lab tests confirmed that all had active Zika infection. Patients were asked to fill out a form to record their symptoms and underwent an initial electrocardiogram, a test that displays the electrical activity of the heart, which in eight cases was suggestive of a problem with the rate or rhythm of their heartbeat. These findings prompted researchers to perform a full cardiovascular work up using an echocardiogram, (24-hour) Holter monitor and a cardiac magnetic resonance imaging study. Of the nine patients, six were female with a mean age of 47 ± 17 years. They were followed for an average of six months, beginning in July 2016.

Dangerous arrhythmias were detected in eight of the nine patients: three cases of atrial fibrillation, two cases of non-sustained atrial tachycardia and two cases of ventricular arrhythmias, which can be deadly. Heart failure was present in six cases. Of these, five patients had heart failure with low ejection fraction—when the amount of blood the heart is able to squeeze out is much less than what it normally would be—and one had heart failure with preserved ejection fraction along with pre-eclampsia and a moderate to severe amount of fluid around the heart (called pericardial effusion). So far, none of the patients' cardiac issues have resolved, though symptoms are much improved due to guideline-directed treatment for or atrial fibrillation. Of note, cardiovascular symptoms tend to manifest later in the process. Data show an average lag of 10 days from patients' initial complaints of Zika symptoms to reports of symptoms suggestive of heart problems.

"Since the majority of people with Zika virus infections present with mild or non-specific symptoms and symptoms of cardiovascular complications may not occur right away, we need to raise awareness about the possible association," Carta said.

Although cardiovascular manifestations are fairly rare against the total number of patients treated at the clinic, Carta believes many more cases will be diagnosed, not only in patients with clear symptoms, but also among those with less severe or no signs of myocarditis, an inflammation of the myocardium, the middle layer of the heart wall. Myocarditis can affect the heart's muscle and electrical system.

"It's likely that many more people are affected, especially as many clinicians and people may not make the connection between symptoms," 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."

For now, she advises that people who are traveling to areas with known Zika virus consider talking with their doctor so they know what basic measures can be taken to prevent infection. Researchers are continuing to follow these patients and are setting up new strategies to screen more patients for cardiovascular problems.

Symptoms of the Zika virus usually include mild fever, skin rash, conjunctivitis (pink eye), muscle and joint pain, malaise or headache, which typically last for two to seven days, according to the World Health Organization. The best way to prevent the Zika virus is by preventing mosquito bites.

While this study points to another potential risk of Zika virus infection, it is limited due to its small size. What remains unclear is whether and how the Zika virus might affect people with existing heart disease. However, Carta says that based on our knowledge of other arboviral infections, patients who have pre¬-existing tend to have worse outcomes.

Carta will present the study, "Myocarditis, Heart Failure and Arrhythmias in Patients With Zika," on Saturday, March 18, 2017, at 1:30 p.m. ET at Poster Hall C at the American College of Cardiology's 66th Annual Scientific Session in Washington. The meeting runs March 17-19.

Explore further: Heart palpitations should not be ignored

Related Stories

Heart palpitations should not be ignored

February 7, 2017
Does the sight of your loved one make your heart skip a beat … literally? Well, that may not be a good thing. Doctors at Baylor College of Medicine say while heart palpitations are common, they should not be ignored.

Zika Virus in the Southeast

October 3, 2016
As of the end of July 2016, there have been 1,658 cases of Zika virus infections diagnosed in the United States. It is believed that most of these infections were contracted outside the United States. While the Zika virus ...

Zika virus: Five things to know

February 8, 2016
A concise "Five things to know about.... Zika virus infection" article for physicians highlights key points about this newly emerged virus in CMAJ (Canadian Medical Association Journal)

Officials: Zika spread through sex by man with no symptoms

August 26, 2016
U.S. health officials on Friday reported the first case of Zika spread through sex by a man with no symptoms of the disease.

Team finds myocarditis caused by infection on rise globally

November 29, 2016
Myocarditis, an assortment of heart disorders often caused by infection and inflammation, is known to be difficult to diagnose and treat. But the picture of who is affected is becoming a little clearer. Men may be as much ...

Argentina: 1st local transmission of Zika, likely by sex

February 26, 2016
Argentine authorities say they've detected the country's first case of local infection with the Zika virus and say it's apparently due to sexual transmission.

Recommended for you

Novel therapies for multidrug-resistant bacteria

October 23, 2017
During this innovative study published in PLOS One, researchers found that novel classes of compounds, such as metal-complexes, can be used as alternatives to or to supplement traditional antibiotics, which have become ineffective ...

Pneumonia vaccine under development provides 'most comprehensive coverage' to date, alleviates antimicrobial concerns

October 20, 2017
In 2004, pneumonia killed more than 2 million children worldwide, according to the World Health Organization. By 2015, the number was less than 1 million.

Newly discovered viral marker could help predict flu severity in infected patients

October 20, 2017
Flu viruses contain defective genetic material that may activate the immune system in infected patients, and new research published in PLOS Pathogens suggests that lower levels of these molecules could increase flu severity.

Migraines may be the brain's way of dealing with oxidative stress

October 19, 2017
A new perspective article highlights a compelling theory about migraine attacks: that they are an integrated mechanism by which the brain protects and repairs itself. Recent insightful findings and potential ways to use them ...

H7N9 influenza is both lethal and transmissible in animal model for flu

October 19, 2017
In 2013, an influenza virus that had never before been detected began circulating among poultry in China. It caused several waves of human infection and in late 2016, the number of people to become sick from the H7N9 virus ...

Flu simulations suggest pandemics more likely in spring, early summer

October 19, 2017
New statistical simulations suggest that Northern Hemisphere flu pandemics are most likely to emerge in late spring or early summer at the tail end of the normal flu season, according to a new study published in PLOS Computational ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.