As a doctor as opposed to an AI researcher, so many of the choices this study makes are baffling to me.<p>First of all, why just one heartbeat? You never capture just one heartbeat on an ECG anyway, and "Is the next heartbeat identical to the first one?" is such an important source of information, it seems completely irrational to exclude it. At least pick TWO heartbeats. If you're gonna pick one random heartbeat, how do you know you didn't pick an extra systole on accident? (Extra systoles look different, and often less healthy, than "normal" heart beats, as they originate from different regions of the heart.)<p>Secondly, why heart failure and not a heart attack? One definition of heart failure is "the heart is unable to pump sufficiently to maintain blood flow to meet the body's needs," which can be caused by all sorts of factors, many of them external to the actual function of the heart - do we even know for sure that there are ANY ECG changes definitely tied to heart failure? Why not instead try to detect heart attacks, which cause well-defined and well-researched known ECG changes?<p>(I realize AIs that claim to be able to detect heart attacks already exist. None of the ones I've personally worked with have ever been usable. The false positive rate is ridiculously high. I suppose maybe some research hospital somewhere has a working one?)