Two-Week Heart Monitor Finds More Dangerous Rhythm Problems After Fainting

A two-week wearable heart monitor fitted to patients who arrive at the emergency room with unexplained fainting more than doubled the detection of dangerous heart rhythm problems, according to a trial presented at the European Society of Cardiology (ESC) Congress in Munich and published in the New England Journal of Medicine.

The device, about the size of a car key fob, is worn continuously in the middle of the chest for two weeks. In the trial, led by Professor Matthew Reed of the University of Edinburgh, half of 2,234 patients who arrived at 45 UK emergency departments with unexplained fainting were fitted with the new monitor, while the other half received standard care.

After one year, heart rhythm problems called arrhythmias were identified in 22% of patients who wore the new monitor, compared with 9% of those who received standard care. Arrhythmias were found in an average of 22 days with the chest-worn monitor, versus 54.5 days under standard care. These included life-threatening arrhythmias such as complete heart block, ventricular tachycardia and pauses in the heartbeat of more than six seconds.

The death rate after one year was 1.5% in the group that used the new monitor, compared with 2.9% in the standard-care group. Monitoring with the new device began within 72 hours of a patient's emergency room visit. Patients under standard care were typically referred instead to a Holter monitor, worn for only 48 hours, and an outpatient cardiology clinic anywhere from six weeks to two years later.

Researchers estimate that around 650,000 people visit the ER with unexplained fainting each year in the UK. There was no difference in the average number of fainting episodes reported after one year: 1.37 in the monitor group, compared with 1.58 in the standard-care group.