Blog – Medical Research News and Interviews

31 Mar Smartphone App Detects Cardiac Arrest During Exercise

MedicalResearch.com Interview with: [caption id="attachment_22952" align="alignleft" width="150"] Dr. Nicola Gaibazzi[/caption] Dr. Nicola Gaibazzi Department of Cardiology Parma University Hospital Parma Italy MedicalResearch.com: What is the background for this study? What are the main findings? Dr. Gaibazzi: As clinical and research cardiologists we have never accepted that cardiac arrests are so frequently deadly throughout the world (sudden cardiac arrest is the world’s leading cause of death) because many of such events could be easily reversed by early defibrillation if only witnessed by a bystander who could quickly call emergency in place of the incapacitated subject. This would be lifesaving for most of them, gaining quick  access to defibrillation within the golden 8-10 minutes (in the Oregon state study 6.5 minutes is the average time from call to defibrillation). While this issue of early defibrillation access is not easy to be solved for cardiac arrest in the general population, it was surprising to us that there was no available tool to date to automatically alert emergency contacts for people who regularly practice outdoor sports alone, such as running or cycling, and may undergo sudden and unexpected sports-associated cardiac arrest. It is a rare event, but it may happen during exercise, when cardiac arrest is actually several times more frequent than during resting condition, both in sedentary and active subjects. It was surprising to us seeing all people practicing with their earbuds, listening to music from their last-generation smartphone, often used only as if it were an old music cassette “walkman”, while it is a powerful and wireless-connected portable computer with an incredible potential for emergency rescue. Consequently, in 2015 we founded a startup company (www.parachute-app.com or temporary new site http://nicolagaibazzi.wix.com/mysite) and started building an app that could take advantage of the capabilities of modern smartphones to automatically detect sports-associated cardiac arrest, specifically aiming at recognizing ventricular tachycardia or ventricular fibrillation. This was not an easy task, since we wanted to use simple, cheap and commercially-available hardware, possibly already at hand for sportspeople; otherwise too few subjects would use it and you would not impact such infrequent disease with only few sportsmen using it, since sports-associated cardiac arrest is rare (2/100000 athletes/year) but not negligible, with 2450 deaths in US only each year. We finally chose to use as the only additional required hardware a BT+ heart rate monitor chest strap (a chest strap can be bought if not already owned at 40$), which is cheap, reliable, able to transmit heart rate with trivial battery drainage detected through cardiac electrical signal with trivial battery drainage, and much more reliable than pulse-plethysmographic methods which fully depend on the device contact with the arm or wrist skin to collect a correct signal. We could not afford in our lifesaving app that a wrong wrist or arm device contact would cause absence of pulse signal detection erroneouslytriggering a cardiac arrest alert or not doing so when a cardiac arrest is truly present. Chest straps on the contrary send heart rate sensed from electrical heart activity and are almost impossible to displace even in case of an unconscious subject falling down. We built and tested our Parachute app for the iPhone during 2015, through long testing in the outdoor field and with arrhythmia simulators and at the ACC congress we present just part of the data collected from such tests in athletes running and cycling and with advanced arrhythmia simulators. Parachute was incredibly accurate both to avoid false positives and false negatives, thanks to continuously combined chest strap heart rate data and motion or, better, detection of “no motion”, corresponding to a possible incapacitated subject. These two mechanisms act together and complete each other, they are synergic, since while our patent-pending algorithm using heart rate data is very sensitive for serious arrhythmias, motion detection can easily exclude false positives during outdoor sports, where motion is by definition almost continuous.