Energy drinks 'could trigger cardiac arrest'

People with high blood pressure or heart problems should be careful about consuming 'energy drinks' as they could trigger cardiac arrest, doctors warn. The drinks, which often contain large amounts of caffeine and other stimulants like taurine, raise blood pressure and could raise the chance of having an irregular heartbeat, they concluded after looking at results from seven studies. The US doctors said the evidence energy drinks raised blood pressure was "convincing and concerning". Specifically, they found energy drinks raised systolic blood pressure by 3.5 points. It also lengthened a phase of the heart's electrical cycle called the 'QT interval'. Having a long QT interval is a sign a person is at greater risk of suffering from an irregular heartbeat, which can be fatal. They concluded that drinking one to three cans raised the QT interval by 10 milliseconds. Professor Sachin Shah from the University of the Pacific in California, said: "Doctors are generally concerned if patients experience an additional 30 milliseconds in their QT interval from baseline."