Based on my prior knowledge, persistent atrial fibrillation can be a possible risk factor for chronic heart failure. Therefore, there is a possibility that the presence of persistent atrial fibrillation in the anamnesis (nr_04 feature) may indicate chronic heart failure.

Here is the generated dictionary based on the analysis:

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

Explanation:
- For the target class "no" (patient does not have chronic heart failure), the possible value for feature nr_04 is "no".
- For the target class "yes" (patient has chronic heart failure), the possible value for feature nr_04 is "yes".

Since the feature is categorical with only two categories, the dictionary includes all possible values for both target classes.