Predicting paroxysmal atrial fibrillation/flutter

The new PhysioNet website is available at: We welcome your feedback.

A challenge from PhysioNet and Computers in Cardiology 2001

22 September 2001: The deadline for entries has passed and no further entries will be accepted. The final scores have now been posted here, together with links to the abstracts submitted by entrants for presentation at Computers in Cardiology.

Papers presented by participants in this challenge are now available.


Following the success of the first Computers in Cardiology Challenge, we are pleased to offer a new challenge from PhysioNet and Computers in Cardiology 2001. The challenge is to develop a fully automated method to predict the onset of paroxysmal atrial fibrillation/flutter (PAF), based on the ECG prior to the event. The goal of the contest is to stimulate effort and advance the state of the art in this clinically significant problem, and to foster both friendly competition and wide-ranging collaborations.

Data for development and evaluation

PhysioNet provides free access to a set of data to be used for development and evaluation of algorithms. The PAF Prediction Challenge Database consists of 100 pairs of half-hour ECG recordings. Each pair of recordings is obtained from a single 24-hour ECG. Subjects in group A experienced PAF; for these subjects, one recording ends just before the onset of PAF, and the other recording is distant in time from any PAF (there is no PAF within 45 minutes before or after the excerpt). Subjects in group N do not have PAF; in these, the times of the recordings have been chosen at random.

The database is divided into a learning set and a test set of equal size, each containing approximately equal numbers of subjects from groups A and N. The classifications of the recordings in the learning set are provided; those for the test set will be revealed after the conclusion of the challenge.

Events and scoring

We will award prizes of US$500 to the most successful entrant in each of two events:

Event 1: PAF screening
Event 1 is intended to determine if subjects in group A can be distinguished from those in group N. (In other words, can individuals at risk of PAF be identified within a larger population, based on their ECGs?) The number of correctly classified subjects (0 to 50) is the event 1 score.
Event 2: PAF prediction
Event 2 is intended to determine if subjects in group A have distinctive and detectable changes in their ECGs immediately before PAF. (In other words, is the imminent onset of PAF predictable in an individual known to be at risk of PAF?) A successful method for doing so should be able to determine which record of each pair of group A records immediately precedes PAF. If the identities of the group A records were known, it would be sufficient to classify these records only; since the goal of event 1 is to identify group A, however, we have not provided this information! Entrants in event 2 of the challenge must therefore classify exactly one of each pair of records in the test set as `A' (defined as ``immediately preceding PAF, if the patient belongs to group A''), and the other as `N' (defined as ``not immediately preceding PAF''). One point is awarded for each correctly classified record pair, so that the event 2 scores range from n to 50 (the lower bound is n, the number of subjects in group N, because the group N subjects are always considered correctly classified).

If a tie occurs in either event, the date of the submission is the tiebreaker.

How to enter

To enter the competition:

  1. Develop an algorithm for classifying the test set recordings. The algorithm must perform this task unaided (manual and semiautomated methods are not eligible).
  2. Submit your classifications to PhysioNet for scoring (click here for detailed instructions).
  3. Submit an abstract with a concise description of your approach and results to Computers in Cardiology 2001. (Deadline: 1 May 2001). Please submit your abstract using the category ECG: Arrhythmia.

If your abstract is accepted, you will be expected to prepare a four-page paper for presentation during the conference and publication in the conference proceedings. We welcome and encourage contributions to PhysioNet of software developed during this competition.

If you wish to improve your score, you may revise your entry and submit it again for scoring. The number of submissions is limited (you will be allowed six entries, which may be all in one event, or divided between the two events as you wish). If you wish to submit additional entries, the autoscorer will enforce a waiting period, which is 24 hours for the seventh entry and doubles for every subsequent entry.

If you have submitted an abstract to Computers in Cardiology 2001 on or before 1 May 2001, you are eligible for awards based on any scores you receive before the challenge deadline of noon GMT on Friday, 21 September 2001.

If you have not submitted an abstract on or before 1 May, you may still participate in the challenge as an unofficial entrant, but you will not be eligible for an award. If you achieve a high score, it will appear in the list of top scores.