A smart-technology wearable wristband may be able to automatically detect cardiac arrest, potentially leading to faster medical assistance and improved survival odds for out-of-hospital events, according to new research published today in Circulation: Arrhythmia and Electrophysiology, a peer-reviewed 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 rhythm—pulseless ventricular tachycardia (pVT) or ventricular fibrillation (VF)—was briefly induced during treatment to correct irregular heartbeats. The algorithm-based wristband detected cardiac arrest 92% of the time, including 100% of VF episodes and 90% of pVT episodes.
“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 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 device uses a light-based technique (photoplethysmography algorithm) to continuously monitor blood flow changes in the wrist. This differs from previous approaches because it allows unobtrusive monitoring in daily life, said 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 for cardiac arrest detection.
“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.
Over 125 hours of recording, the algorithm recorded 59 shockable cardiac arrest events with nine false positives. In per-patient analysis, accuracy was 92%. Cameron Dezfulian, M.D., FAHA, chair of the American Heart Association’s Resuscitation Science Symposium Program Committee, who was not involved in the study, noted the low false-positive rate as impressive. “This study parallels findings from a study in Canada and one in the U.S. that shows this technology has great potential,” he said. However, he cautioned that pulseless electrical activity remains the most common presenting rhythm in cardiac arrest and accounts for a small portion of validation data for such sensors.
The research was conducted in a controlled clinical setting, so effectiveness in real-world conditions still needs evaluation. The DETECT project, a collaboration of several hospitals and a company in the Netherlands, aims to develop a smart wristband that can automatically detect cardiac arrest and alert emergency services. “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.
Study participants had a median age of 66 years, and 84% were men. Seven underwent implantable defibrillator implantation and 43 had ablation. The findings were published in Circulation: Arrhythmia and Electrophysiology on May 19, 2026.
