75 percent patients of fainting need only 2 hours of monitoring in ED: Circulation

The optimal duration of cardiac rhythm monitoring following emergency department (ED) presentation for fainting (syncope) is poorly described. Venkatesh Thiruganasambandamoorthy, Department of Emergency Medicine, University of Ottawa, Canada, and colleagues sought to describe the incidence and time to arrhythmia occurrence to inform decisions regarding the duration of monitoring based on ED risk-stratification.

"Before this study, we didn't know which fainting patients needed to be monitored in the Emergency Department, and how long they needed to be monitored. We didn't know who needed to be hospitalized in order to catch life-threatening conditions. Now we have answers to these questions that will help improve patient care, and potentially reduce ED wait times and hospital admissions." said Dr. Thiruganasambandamoorthy.

In this observational study, they used the tool to rank 5,581 patients from six EDs across Canada as low (0.4 percent risk of an arrhythmia within 30 days), medium (8.7 percent) or high risk (25.3 percent). They collected baseline characteristics, time of syncope and ED arrival, and the Canadian Syncope Risk Score (CSRS) risk category.

Out of the 5,581 people, 74 percent were classified as low-risk, 19 percent as medium-risk and 7 percent as high-risk. One month after fainting, 3.7 percent of individuals (207) suffered an arrhythmia.

Key Findings:

• 5,581 patients (mean age 53.4 years, 54.5% females, 11.6% hospitalized) were available for analysis, including 346 (6.2%) for whom the 30-day follow-up was incomplete and were censored at the last follow-up time.


• 417 (7.5%) patients suffered serious outcomes of which 207 (3.7%) were arrhythmic (161 arrhythmias, 30 cardiac device implantations, 16 unexplained death).


• Overall, 4123 (73.9%) were classified as CSRS low-risk, 1062 (19.0%) medium and 396 (7.1%) high-risk.


• The CSRS accurately stratified subjects as low (0.4% risk for 30-day arrhythmic outcome), medium (8.7% risk) and high-risk (25.3% risk).


• One-half of arrhythmic outcomes were identified within 2-hours of ED arrival in low-risk and within 6-hours in medium and high-risk patients and the residual risk after these cut-points were 0.2% for low-risk, 5.0% medium and 18.1% high-risk patients.


• Overall, 91.7% of arrhythmic outcomes among medium and high-risk patients including all ventricular arrhythmias were identified within 15-days.


• None of the low-risk patients suffered ventricular arrhythmia or unexplained death while 0.9% medium-risk and 6.3% of high-risk patients suffered them.

"Our study suggests that three-quarters of the 200,000 fainting patients who come to Canadian Emergency Departments every year are at low risk of adverse events. They can safely be sent home once they've been in the ED two hours and a physician sees them," said Dr. Thiruganasambandamoorthy.

"Outpatient cardiac rhythm monitoring for 15-days for selected medium-risk patients and all high-risk patients discharged from the hospital should also be considered," concluded the authors.

For further reference log on to https://doi.org/10.1161/CIRCULATIONAHA.118.036088