Based on prior knowledge, there is a known relationship between atrial fibrillation (represented by the 'yes' category of feature "ritm_ecg_p_02") and chronic heart failure. Therefore, if a patient has atrial fibrillation, it is likely that they have chronic heart failure.

Based on this analysis, the dictionary for the feature "ritm_ecg_p_02" and the task of determining if the patient has chronic heart failure would be as follows:

```json
{
  "no": ["no"],
  "yes": ["yes"]
}
```

The dictionary indicates that if the value of the feature "ritm_ecg_p_02" is "no," it suggests that the patient does not have chronic heart failure. If the value is "yes," it suggests that the patient does have chronic heart failure.