Smart wristbands may help prevent cardiac arrest deaths

The wearable technology could lead to quicker responses for out-of-hospital cardiac arrests among heart patients and increased survival rates, suggests the study.

The DETECT‑1b study analyzed data from 49 adults, average age 66, in the Netherlands with abnormal heart rhythms.

They had all undergone 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.

Doctors say 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, according to the findings published in the journal Circulation.

Only nine events were classified as false positives during 125 hours of recording.

Study senior author Dr. Judith Bonnes said: "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."

Bonnes, a cardiologist at Radboud University Medical Center, Nijmegen, added: "With the device automatically notifying emergency services or nearby trained responders, help could arrive sooner, which may significantly improve survival chances."

The study examined whether a medically certified smart technology wristband that continuously monitors vital signs can detect when the heart suddenly stops pumping blood.

The device studied uses a light-based technique, called photoplethysmography algorithm, to measure changes in blood flow in the wrist.

Study lead author Roos Edgar, a technical physician at Radboud University Medical Center, says the wrist-based photoplethysmography algorithm differs from previous approaches to detecting cardiac arrest because it allows continuous and unobtrusive monitoring in daily life.

Many commercially available smart watches use similar sensors, but most are not designed to detect cardiac arrest.

Edgar said: "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."

The research team say the algorithm from the study could be used to alert nearby lay rescuers, emergency services, or both, when someone having a cardiac arrest is detected.

Bonnes added: "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."

Dr. Cameron Dezfulian, chair of the American Heart Association's Resuscitation Science Symposium Program Committee, welcomed the "exciting" findings.

Dezfulian, from Baylor College of Medicine, Houston, said: "What is more impressive than the ability of this technology to detect cardiac arrest is the fairly low frequency of false positives it detected."

He added: "This study parallels findings from a study in Canada and one in the U.S. that shows this technology has great potential.

"Pulseless electrical activity remains the most common presenting rhythm in all cardiac arrest.

"However, it accounts for a small number of the validation data for such wearable sensors."

Bonnes added that the system's effectiveness and reliability in real-world conditions still need to be evaluated in further studies.