A new diagnostic technique that uses a smartphone could allow people to spot the hallmarks of heart failure faster than traditional methods allow. Developed by organizations in Finland and the United States, the technique uses the motion sensors built into today's smartphones to detect vibrations in the chest. These vibrations often appear as a result of underlying cardiac issues that lead to heart failure.
Heart failure is a condition, not a disease unto itself. Caused or exacerbated by any number of acute diagnoses—like coronary artery disease, heart valve disorders, high blood pressure, and more—heart failure marks the heart's inability to pump sufficient blood. Even if the heart is semi-operational, it might not be able to achieve the level of efficiency required by the rest of the body, leading to kidney damage, liver damage, blood clots, or death with time.
The diseases that cause heart failure often give rise to unusual cardiac vibrations, which can be used for diagnostic purposes. These vibrations divert from the heart's typical movements when the heart can't contract or relax regularly, a valve doesn't open or close properly, or a chamber of the heart is enlarged. And while medical professionals can use seismocardiography instruments to record these vibrations, those instruments aren't easily accessible; after getting a referral from a primary care provider, patients worried about their heart health must often wait weeks for an appointment with a cardiologist.
Soon, people might be able to use their phones to spot cardiac red flags. Researchers at the University of Turku have spent the last 10 years working to leverage smartphone motion sensors—typically used for fitness data, navigation assistance, and gaming—for mobile seismocardiography. Now, in a paper for the Journal of the American College of Cardiology: Heart Failure, they write that a phone can successfully pick up on cardiac vibrations.
To use their technique, a patient simply lies on their back and then places their phone face-up on their chest. As the heart's vibrations transmit through the patient's chest wall, the phone's accelerometer and gyroscope pick up on each movement, allowing the vibrations to be visualized on a graph. The process takes only one minute.
Just over 1,000 patients have tested the technology in experiments at Finland's Turku and Helsinki University Hospitals and Stanford University Hospital. Of them, 217 patients had already been diagnosed with heart failure. Researchers found that their smartphone vibration detection method picked up on heart failure-related vibration patterns with 89% accuracy—a success rate of roughly 9 out of every 10 patients.
The University of Turku worked with CardioSignal, a Finnish startup, to perfect the technology. CardioSignal currently offers atrial fibrillation detection through the CardioSignal smartphone app. Depending on future trials, the app could eventually incorporate the University of Turku's general heart failure detection.
