A smart-technology wearable wristband may be able to automatically detect cardiac arrest, potentially improving survival odds by enabling faster medical assistance when cardiac arrest occurs outside a hospital, according to new research published today in Circulation: Arrhythmia and Electrophysiology, a peer-reviewed scientific journal of the American Heart Association.
The DETECT‑1b study analyzed data from 49 adults in the Netherlands with abnormal heart rhythms who underwent a medical procedure in which a life-threatening heart rhythm was briefly induced. The algorithm-based wristband detected cardiac arrest in 92% of cases, specifically identifying 100% of ventricular fibrillation and 90% of pulseless ventricular tachycardia events.
“Our findings are important because many out-of-hospital cardiac arrests are unwitnessed. A smart technology wristband capable of automatically detecting cardiac arrest and triggering an alert could function as a digital witness,” said study senior author Judith Bonnes, M.D., Ph.D., a cardiologist at the Radboud University Medical Center in Nijmegen, Netherlands. “With the device automatically notifying emergency services or nearby trained responders, help could arrive sooner, which may significantly improve survival chances.”
The wristband uses a photoplethysmography algorithm that measures changes in blood flow in the wrist via light-based technology. Unlike previous approaches, this method allows continuous and unobtrusive monitoring in daily life, according to lead study author Roos Edgar, M.Sc., a technical physician at Radboud University Medical Center. Many commercially available smart watches use similar sensors, but most are not designed to detect cardiac arrest.
“This is the first study to externally validate such an algorithm using patient data, which is an important step toward developing a reliable detection system for real-world use,” Edgar said.
A total of 59 shockable cardiac arrest events were recorded during the study. Nine events were classified as false positives during 125 hours of recording. In a per-patient analysis considering only the first event per person, accuracy for detecting irregular rhythms was 92%.
“What is more impressive than the ability of this technology to detect cardiac arrest is the fairly low frequency of false positives it detected,” said Cameron Dezfulian, M.D., FAHA, chair of the American Heart Association’s Resuscitation Science Symposium Program Committee, who was not involved in the study. “This study parallels findings from a study in Canada and one in the U.S. that shows this technology has great potential.”
However, Dezfulian noted that pulseless electrical activity remains the most common presenting rhythm in cardiac arrest but accounts for a small portion of validation data for such wearable sensors, indicating a need for further research.
The research was conducted in a controlled clinical setting, which is a limitation. The system’s effectiveness and reliability in real-world conditions still need evaluation in future studies, Bonnes said. The DETECT project, a collaboration of several hospitals and a company in the Netherlands, aims to develop a smart wristband for automated detection of cardiac arrest and alerting emergency services.
In a future application, the algorithm could alert nearby lay rescuers, emergency services, or both. “The goal is to connect the wristband to emergency dispatch centers and volunteer responder networks in the Netherlands so that nearby rescuers and ambulance services can be alerted immediately when cardiac arrest is detected,” Bonnes said.
