Based on prior knowledge, how paroxysms of atrial fibrillation in the anamnesis (feature nr_03) may relate to the presence of chronic heart failure (target variable) can be determined. The possible relationship between the feature and task is as follows:

1. If the value of feature nr_03 is "no", then there is a possibility that the patient does not have chronic heart failure.
2. If the value of feature nr_03 is "yes", then there is a possibility that the patient has chronic heart failure.

Based on this analysis, the dictionary can be created as follows:

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

Please note that in this case, we only have two possible values for feature nr_03, which are "no" and "yes". Therefore, the possible values for each target class are listed accordingly.