Drinking energy drinks may make your heart's rhythm go haywire and also increase your blood pressure, a new study says.

A recent report from a federal agency had said that ER visits linked to drinking too much energy drinks doubled from 10,000 in 2007 to almost 21,000 in 2011.

The present study was based on analysis of data obtained from seven trials that had looked into the effects of energy drinks. First, researchers analyzed the QT interval of 93 people who had consumed one to three servings of the energy drinks. They found that, on average, QT interval was 10 milliseconds longer for people when they had the drinks. A longer interval between Q and T in an electrocardiogram depicts risk of sudden heart death.

"Doctors are generally concerned if patients experience an additional 30 milliseconds in their QT interval from baseline," said Sachin A. Shah, lead author and assistant professor at University of the Pacific in Stockton, Calif.

The data also showed a 3.5 point increase in systolic blood pressure - the number written on top on a blood pressure reading - in a group of 132 people enrolled in the trial. The study had included healthy, young people between ages 18 and 45 years.

"The correlation between energy drinks and increased systolic blood pressure is convincing and concerning, and more studies are needed to assess the impact on the heart rhythm. Patients with high blood pressures or long QT syndrome should use caution and judgment before consuming an energy drink," Shah said.

"Since energy drinks also contain caffeine, people who do not normally drink much caffeine might have an exaggerated increase in blood pressure," Shah added in a news release.

The study was presented at the American Heart Association's Epidemiology and Prevention/Nutrition, Physical Activity and Metabolism 2013 Scientific Sessions.

A recent study published in the journal Pediatrics had found that some 30 to 50 percent of teenagers and young adults consumed energy drinks. Health complications like cardiac abnormalities, diabetes and seizures can occur in people who drink high amounts of these energy drinks. In 2011, sales of these drinks touched $9 billion.