Based on prior knowledge, we can analyze the relationship between the feature "np_04" and the occurrence of chronic heart failure in the patient.

Since "np_04" represents the presence or absence of third-degree AV block in the anamnesis, it indicates a potential cardiac condition. Third-degree AV block is a serious conduction disorder in which electrical impulses are completely blocked between the atria and ventricles of the heart. Chronic heart failure can be a consequence of the impaired electrical conduction.

Therefore, it is reasonable to expect that patients with a positive history of third-degree AV block (np_04 = 'yes') might have a higher likelihood of developing chronic heart failure. On the other hand, patients without such a history (np_04 = 'no') may have a lower likelihood of having chronic heart failure.

Based on this analysis, we can create the dictionary as follows:

```json
{
    "no": ["no"],
    "yes": ["yes"]
}
```
Since the feature "np_04" is a categorical variable with only two possible values, we include each value in the respective target class list.