Researchers are now planning a number of new clinical studies, including assessing morphological variability in healthy people to get a sense of how this measure varies among a normal population. (The existing research was done on recordings from patients with a history of heart disease.) In addition, the team is modifying the algorithm to shorten the amount of data needed to make the predictions from about 10 hours’ worth of EKG data to less than one. “We hope to get it down to half an hour, which is within the realm of a doctor’s visit,” says Guttag.
They also want to determine whether measuring morphological variability in patients at high risk of developing cardiovascular disease can predict risk of heart attack or death in those who have not yet had a cardiac event.
“It’s an extra test, but it’s one that is cheap, because the data is already available and the analysis can be performed on existing computers,” says Guttag. But the technology still faces a number of hurdles. A prospective trial is needed to confirm that morphological variability is a clinically useful marker. And researchers need to figure out how cardiologists can easily access and analyze the information–the different devices currently used to record EKGs typically lock the data behind protective software.
In the longer term, the researchers aim to incorporate this type of analysis into a new generation of heart monitors currently under development. These monitors are intended to be so small, cheap, and easy to use that people wear them all the time–similar to the heart-rate monitors athletes often wear but able to collect more sophisticated information.
The team is collaborating with Texas Instruments to develop a wearable monitor with an embedded chip to calculate morphological variability in real time. Such a device might be used to signal a patient to take additional medication or signal an implanted device to deliver a jolt of electricity to the heart.
Cardiologists themselves may prove to be a serious obstacle in bringing this type of analysis to clinical practice. Not only is morphological variability too subtle a measure to detect visually, it is not yet clear what it represents physically in the heart. “It’s going to be difficult for a nonengineer to link this measurement to specific abnormal electrophysiological phenomena,” says Couderc. “That needs to be clarified and communicated to the medical field.”