The PhysioNet/CinC Challenge encourages the development of algorithms to classify, from a single short ECG lead recording (between 30 s and 60 s in length), whether the recording shows normal sinus rhythm, atrial fibrillation (AF), an alternative rhythm, or is too noisy to be classified.

There are various types of cardiac arrhythmias that may be classified by the following:

• Origin: atrial arrhythmia, junctional arrhythmia, or ventricular arrhythmia.
• Rate: tachycardia (> 100 beats per minute (bpm) in adults) or bradycardia (< 60 bpm in adults).
• Mechanism: automaticity, re-entry, triggered.
• AV Conduction: normal, delayed, blocked.
• Duration: non-sustained (less than 30 s) or sustained (30 s or longer).