Zika virus may have harmful effect on heart: study

Zika virus, which is known to cause severe birth defects in babies and a paralysing neurological condition, may also have serious effects on the heart, new research has warned.

The study is the first to report cardiovascular complications related to this virus, researchers said. In the study of nine adult patients with Zika and no previous history of cardiovascular disease, all but one developed a heart rhythm problem and two-thirds had evidence of heart failure.

It is known that Zika can cause microcephaly, a severe birth defect in babies born to women infected with the virus, and Guillain-Barre syndrome, a neurological condition that can lead to muscle weakness and, in severe cases, paralysis.

"We know that other mosquito-borne diseases, such as dengue fever and chikungunya virus, can affect the heart, so we thought we might see the same with Zika. But we were surprised by the severity, even in this small number of patients," said Karina Gonzalez Carta, cardiologist at Mayo Clinic in the US.

The patients, six females, with mean age of 47, were seen at the Department of Tropical Medicine in Venezuela within two weeks of having Zika-type symptoms. They reported symptoms of heart problems, most commonly palpitations followed by shortness of breath and fatigue.

Only one patient had any previous cardiovascular problems (high blood pressure), and tests confirmed that all of the patients had active Zika infection.

Patients underwent an initial electrocardiogram (EKG), a test that shows the electrical activity of the heart, and in eight of the patients, the EKG suggested heartbeat rate or rhythm concerns.

These findings prompted a full cardiovascular workup using an echocardiogram, (24-hour) Holter monitor and a cardiac MRI study.

Serious arrhythmias were detected in eight patients: three cases of atrial fibrillation, two cases of nonsustained atrial tachycardia and two cases of ventricular arrhythmias. Heart failure was present in six cases.

Of these, five patients had heart failure with low ejection fraction, when the heart muscle does not pump blood as well as it should, and one had heart failure with preserved ejection fraction, when the heart becomes stiff and cannot relax or fill properly.

The study appears in the Journal of the American College of Cardiology.