| Here are results reported by Ditto, Spano, and coworkers. |
| Atrial Fibrillation, or AFib, is the most common cardiac arrhythmia requiring treatment. It occurs in over 5% of the population over 65 and increases the risk of stroke and death. |
| These experiments were performed on 25 patients at Emory University. |
| (1) For each patient, AFib was induced and an unstable fixed point determined from the return map of the interbeat intervals. |
| (2) A learning phase determined how the fixed point changed as the stimulus was varied. |
| (3) Then the method of contol was applied to keep the interbeat interval near this fixed point. |
| This method worked in 3/4 of the patients, though in about half of these, the control was more short-lived. |
| Pictured on the right are histograms of the distribution of the return map before (upper graph) and after (lower graph) control was implemented. |
| The strong central spike in the middle of the lower graph demonstrates the effectiveness of the control method. Note the change of vertical scale between the two graphs. |
