DALLAS — A smart-technology wearable wristband may be able to automatically detect cardiac arrest, potentially leading to faster medical assistance and increased survival odds when cardiac arrest occurs outside of 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 for 49 adults in the Netherlands with abnormal heart rhythms who had a medical procedure in which a life-threatening heart rhythm was briefly induced during a routine procedure to correct the irregular rhythm. Pulseless ventricular tachycardia (pVT) or ventricular fibrillation (VF) was induced during treatment. Ventricular fibrillation, considered the most serious abnormal heart rhythm, is extremely dangerous and can lead to sudden cardiac death.
The algorithm‑based wearable wristband detected cardiac arrest 92% of the time. The device uses a light-based technique (photoplethysmography algorithm) to measure changes in blood flow in the wrist.
“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.”
Study results showed that a total of 59 shockable cardiac arrest events were recorded. Cardiac arrest was accurately detected in 92% of cases: specifically, 100% of ventricular fibrillation and 90% of pulseless ventricular tachycardia. Nine events were classified as false positives during 125 hours of recording. In the per-patient analysis, considering only the first event per person, the accuracy for detecting the irregular rhythms was 92%.
This wrist-based photoplethysmography algorithm differs from previous approaches to detecting cardiac arrest because it allows continuous and 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; however, 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,” she said.
In a future application, the algorithm from this study could be used to alert nearby lay rescuers, emergency services, or both, when someone having a cardiac arrest is detected. “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.
Even though this is a small study, the results are exciting, 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. “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 Dezfulian, senior faculty in pediatrics and critical care at Baylor College of Medicine in Houston. “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 all cardiac arrest but accounts for a small number of the validation data for such wearable sensors, emphasizing that further research will be important.
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 to be evaluated in future studies, Bonnes said. The DETECT-1b study was part of the broader DETECT project, a collaboration of several hospitals and a company in the Netherlands conducting studies to develop a smart wristband for the automated detection of cardiac arrest and alerting emergency services.
