Popis: |
We use nonlinear methods to predict changes in cardiac rhythms over periods of up to several hours. The patterns of measured premature heart beats which correspond to return cycles of a 1D map are found to be organized into a devil's staircase when plotted against heart rate. Throughout the data collections, changes in patterns with heart rate agree with the computed dynamics. This result, typical of the majority of patients examined, demonstrates that (1) simple recursions can model complex biological rhythms and (2) mode locking can play a dominant role in the patterning of arrhythmias. |